Data Wrangling with dplyr

Tuesday, October 8

Today we will…

New Material
- Introduce the dplyr package.
- Use dplyr verbs to manipulate data.
PA 3: Identify the Mystery College

Data Wrangling with `dplyr`

A cartoon illustration of a cowboy riding a dataset, symbolized by a saddle on top of a spreadsheet. The cowboy is wearing a hat and bandana, with the reins in one hand and a lasso in the other, as if wrangling data. The dataset underneath has rows and columns, representing organized data. The image humorously conveys the idea of managing and working with data.

Artwork by Allison Horst

`dplyr`

dplyr is part of the tidyverse that provides us with the Grammar of Data Wrangling.

This package gives us the tools to wrangle and tidy our data with ease.
Check out the dplyr cheatsheet.

`dplyr` verbs

filter() – select rows based on their values
select() – select columns
mutate() – add new columns or change existing columns
summarize() – perform summary operations on columns
group_by() – facilitate group-wise operations
arrange() – sort rows based on their values

Use the pipe operator (|> or %>%) to chain together data wrangling operations.

The Pipe Operator

No matter how complex and polished the individual operations are, it is often the quality of the glue that most directly determines the power of the system.

— Hal Abelson

The Pipe Operator

With dplyr, your code should read like a sentence.
The data is the primary object in your sentence, so it should come first in your code.

The pipe operator is an important part of that readability.

The Pipe Operator

The pipe specifies a sequence of operations.
- The output from one operation is passed into the first argument (the dataset) of the next operation.

The “original” pipe: %>%
- Loaded with tidyverse package (part of magrittr).
The “native” pipe: |>
- Created in R version 4.1.0.
- Directions for how to use

The Pipe Operator

dr_theobold |>
  play_a_sport()

dr_theobold |>
  put_on("cleats") |>
  play_a_sport(type = "track")

Data Comes First!

filter(.data = cereal, ...)
select(.data = cereal, ...)
mutate(.data = cereal, ...)

You can choose whether to:

declare your data using the .data argument

summarize(.data = cereal)

pipe your data into the first argument of the function

cereal |> 
  summarize()

I ❤️ |>

The pipe operator is your friend!

You can pipe data or summaries directly into your ggplot2 code for plotting!

cereals |>
  mutate(type = as.factor(type)) |> 
  rename(temp = type) |>  
  filter(temp == "C") |>
  ggplot(mapping = aes(x = calories)) +
    geom_histogram(binwidth = 17)

Example Data set – Cereal

library(liver)
data(cereal)

Data Structure
Data Summary

glimpse(cereal)

Rows: 77
Columns: 16
$ name     <fct> 100% Bran, 100% Natural Bran, All-Bran, All-Bran with Extra F…
$ manuf    <fct> N, Q, K, K, R, G, K, G, R, P, Q, G, G, G, G, R, K, K, G, K, N…
$ type     <fct> cold, cold, cold, cold, cold, cold, cold, cold, cold, cold, c…
$ calories <int> 70, 120, 70, 50, 110, 110, 110, 130, 90, 90, 120, 110, 120, 1…
$ protein  <int> 4, 3, 4, 4, 2, 2, 2, 3, 2, 3, 1, 6, 1, 3, 1, 2, 2, 1, 1, 3, 3…
$ fat      <int> 1, 5, 1, 0, 2, 2, 0, 2, 1, 0, 2, 2, 3, 2, 1, 0, 0, 0, 1, 3, 0…
$ sodium   <int> 130, 15, 260, 140, 200, 180, 125, 210, 200, 210, 220, 290, 21…
$ fiber    <dbl> 10.0, 2.0, 9.0, 14.0, 1.0, 1.5, 1.0, 2.0, 4.0, 5.0, 0.0, 2.0,…
$ carbo    <dbl> 5.0, 8.0, 7.0, 8.0, 14.0, 10.5, 11.0, 18.0, 15.0, 13.0, 12.0,…
$ sugars   <int> 6, 8, 5, 0, 8, 10, 14, 8, 6, 5, 12, 1, 9, 7, 13, 3, 2, 12, 13…
$ potass   <int> 280, 135, 320, 330, -1, 70, 30, 100, 125, 190, 35, 105, 45, 1…
$ vitamins <int> 25, 0, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25…
$ shelf    <int> 3, 3, 3, 3, 3, 1, 2, 3, 1, 3, 2, 1, 2, 3, 2, 1, 1, 2, 2, 3, 2…
$ weight   <dbl> 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.33, 1.00, 1.00, 1…
$ cups     <dbl> 0.33, 1.00, 0.33, 0.50, 0.75, 0.75, 1.00, 0.75, 0.67, 0.67, 0…
$ rating   <dbl> 68.40297, 33.98368, 59.42551, 93.70491, 34.38484, 29.50954, 3…

summary(cereal)

                        name    manuf    type       calories    
 100% Bran                : 1   A: 1   cold:74   Min.   : 50.0  
 100% Natural Bran        : 1   G:22   hot : 3   1st Qu.:100.0  
 All-Bran                 : 1   K:23             Median :110.0  
 All-Bran with Extra Fiber: 1   N: 6             Mean   :106.9  
 Almond Delight           : 1   P: 9             3rd Qu.:110.0  
 Apple Cinnamon Cheerios  : 1   Q: 8             Max.   :160.0  
 (Other)                  :71   R: 8                            
    protein           fat            sodium          fiber       
 Min.   :1.000   Min.   :0.000   Min.   :  0.0   Min.   : 0.000  
 1st Qu.:2.000   1st Qu.:0.000   1st Qu.:130.0   1st Qu.: 1.000  
 Median :3.000   Median :1.000   Median :180.0   Median : 2.000  
 Mean   :2.545   Mean   :1.013   Mean   :159.7   Mean   : 2.152  
 3rd Qu.:3.000   3rd Qu.:2.000   3rd Qu.:210.0   3rd Qu.: 3.000  
 Max.   :6.000   Max.   :5.000   Max.   :320.0   Max.   :14.000  
                                                                 
     carbo          sugars           potass          vitamins     
 Min.   :-1.0   Min.   :-1.000   Min.   : -1.00   Min.   :  0.00  
 1st Qu.:12.0   1st Qu.: 3.000   1st Qu.: 40.00   1st Qu.: 25.00  
 Median :14.0   Median : 7.000   Median : 90.00   Median : 25.00  
 Mean   :14.6   Mean   : 6.922   Mean   : 96.08   Mean   : 28.25  
 3rd Qu.:17.0   3rd Qu.:11.000   3rd Qu.:120.00   3rd Qu.: 25.00  
 Max.   :23.0   Max.   :15.000   Max.   :330.00   Max.   :100.00  
                                                                  
     shelf           weight          cups           rating     
 Min.   :1.000   Min.   :0.50   Min.   :0.250   Min.   :18.04  
 1st Qu.:1.000   1st Qu.:1.00   1st Qu.:0.670   1st Qu.:33.17  
 Median :2.000   Median :1.00   Median :0.750   Median :40.40  
 Mean   :2.208   Mean   :1.03   Mean   :0.821   Mean   :42.67  
 3rd Qu.:3.000   3rd Qu.:1.00   3rd Qu.:1.000   3rd Qu.:50.83  
 Max.   :3.000   Max.   :1.50   Max.   :1.500   Max.   :93.70

`filter()`

Artwork by Allison Horst

`filter()`

We filter to the rows (observations) we would like to keep in the data.

cereal |> 
  filter(sugars < 5)

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8	0	330	25	3	1.00	0.50	93.70491
Cheerios	G	cold	110	6	2	290	2.0	17	1	105	25	1	1.00	1.25	50.76500
Corn Chex	R	cold	110	2	0	280	0.0	22	3	25	25	1	1.00	1.00	41.44502
Corn Flakes	K	cold	100	2	0	290	1.0	21	2	35	25	1	1.00	1.00	45.86332
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21	0	-1	0	2	1.00	1.00	64.53382
Crispix	K	cold	110	2	0	220	1.0	21	3	30	25	3	1.00	1.00	46.89564
Grape-Nuts	P	cold	110	3	0	170	3.0	17	3	90	25	3	1.00	0.25	53.37101
Great Grains Pecan	P	cold	120	3	3	75	3.0	13	4	100	25	3	1.00	0.33	45.81172
Kix	G	cold	110	2	1	260	0.0	21	3	40	25	2	1.00	1.50	39.24111
Maypo	A	hot	100	4	1	0	0.0	16	3	95	25	2	1.00	1.00	54.85092
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18	2	90	25	3	1.00	1.00	59.64284
Product 19	K	cold	100	3	0	320	1.0	20	3	45	100	3	1.00	1.00	41.50354
Puffed Rice	Q	cold	50	1	0	0	0.0	13	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10	0	50	0	3	0.50	1.00	63.00565
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1	-1	110	0	1	1.00	0.67	50.82839
Rice Chex	R	cold	110	1	0	240	0.0	23	2	30	25	1	1.00	1.13	41.99893
Rice Krispies	K	cold	110	2	0	290	0.0	22	3	35	25	1	1.00	1.00	40.56016
Shredded Wheat	N	cold	80	2	0	0	3.0	16	0	95	0	1	0.83	1.00	68.23588
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20	0	120	0	1	1.00	0.67	72.80179
Special K	K	cold	110	6	0	230	1.0	16	3	55	25	1	1.00	1.00	53.13132
Total Corn Flakes	G	cold	110	2	1	200	0.0	21	3	35	100	3	1.00	1.00	38.83975
Total Whole Grain	G	cold	100	3	1	200	3.0	16	3	110	100	3	1.00	1.00	46.65884
Triples	G	cold	110	2	1	250	0.0	21	3	60	25	3	1.00	0.75	39.10617
Wheat Chex	R	cold	100	3	1	230	3.0	17	3	115	25	1	1.00	0.67	49.78744
Wheaties	G	cold	100	3	1	200	3.0	17	3	110	25	1	1.00	1.00	51.59219

`filter()`

We can add multiple filters to our data, to get a more specific subset.

cereal |> 
  filter(sugars < 5,
         type == "hot")

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21	0	-1	0	2	1	1.00	64.53382
Maypo	A	hot	100	4	1	0	0.0	16	3	95	25	2	1	1.00	54.85092
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1	-1	110	0	1	1	0.67	50.82839

Why not use `&`?

The , separating these two conditions is equivalent to using an &. Why not just use a &?

Well, with a lot of &s your code can get hard to read…

filter(sugars < 5 & type == "cold" & calories > 100)

So instead we use commas.

filter(sugars < 5, 
       type == "cold", 
       calories > 100)

`filter()`: Handy Helpers!

> : greater than
< : less than
>= or <=: greater than / less than or equal to
== : equal to
! : not
%in% : checks if an element belongs to a vector
is.na() : binary evaluation of missing values
| : or

`filter()`: `|`

What if I wanted either non-sugary cereals or hot cereals…

cereal |> 
  filter(sugars < 5 |
           type == "hot")

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8	0	330	25	3	1.00	0.50	93.70491
Cheerios	G	cold	110	6	2	290	2.0	17	1	105	25	1	1.00	1.25	50.76500
Corn Chex	R	cold	110	2	0	280	0.0	22	3	25	25	1	1.00	1.00	41.44502
Corn Flakes	K	cold	100	2	0	290	1.0	21	2	35	25	1	1.00	1.00	45.86332
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21	0	-1	0	2	1.00	1.00	64.53382
Crispix	K	cold	110	2	0	220	1.0	21	3	30	25	3	1.00	1.00	46.89564
Grape-Nuts	P	cold	110	3	0	170	3.0	17	3	90	25	3	1.00	0.25	53.37101
Great Grains Pecan	P	cold	120	3	3	75	3.0	13	4	100	25	3	1.00	0.33	45.81172
Kix	G	cold	110	2	1	260	0.0	21	3	40	25	2	1.00	1.50	39.24111
Maypo	A	hot	100	4	1	0	0.0	16	3	95	25	2	1.00	1.00	54.85092
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18	2	90	25	3	1.00	1.00	59.64284
Product 19	K	cold	100	3	0	320	1.0	20	3	45	100	3	1.00	1.00	41.50354
Puffed Rice	Q	cold	50	1	0	0	0.0	13	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10	0	50	0	3	0.50	1.00	63.00565
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1	-1	110	0	1	1.00	0.67	50.82839
Rice Chex	R	cold	110	1	0	240	0.0	23	2	30	25	1	1.00	1.13	41.99893
Rice Krispies	K	cold	110	2	0	290	0.0	22	3	35	25	1	1.00	1.00	40.56016
Shredded Wheat	N	cold	80	2	0	0	3.0	16	0	95	0	1	0.83	1.00	68.23588
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20	0	120	0	1	1.00	0.67	72.80179
Special K	K	cold	110	6	0	230	1.0	16	3	55	25	1	1.00	1.00	53.13132
Total Corn Flakes	G	cold	110	2	1	200	0.0	21	3	35	100	3	1.00	1.00	38.83975
Total Whole Grain	G	cold	100	3	1	200	3.0	16	3	110	100	3	1.00	1.00	46.65884
Triples	G	cold	110	2	1	250	0.0	21	3	60	25	3	1.00	0.75	39.10617
Wheat Chex	R	cold	100	3	1	230	3.0	17	3	115	25	1	1.00	0.67	49.78744
Wheaties	G	cold	100	3	1	200	3.0	17	3	110	25	1	1.00	1.00	51.59219

`filter()`: `%in%`

Are you interested in observations with values in a list of levels?

cereal |> 
  filter(name %in% c("Cheerios", 
                     "Cinnamon Toast Crunch", 
                     "Raisin Bran", 
                     "Cracklin' Oat Bran")
         )

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
Cheerios	G	cold	110	6	2	290	2	17	1	105	25	1	1.00	1.25	50.76500
Cinnamon Toast Crunch	G	cold	120	1	3	210	0	13	9	45	25	2	1.00	0.75	19.82357
Cracklin' Oat Bran	K	cold	110	3	3	140	4	10	7	160	25	3	1.00	0.50	40.44877
Raisin Bran	K	cold	120	3	1	210	5	14	12	240	25	2	1.33	0.75	39.25920

How do we “filter” in base `R`?

You can use the subset() function!

cereal |> 
  subset(name %in% c("Cheerios", 
                     "Cinnamon Toast Crunch", 
                     "Raisin Bran", 
                     "Cracklin' Oat Bran")
         )

	name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
12	Cheerios	G	cold	110	6	2	290	2	17	1	105	25	1	1.00	1.25	50.76500
13	Cinnamon Toast Crunch	G	cold	120	1	3	210	0	13	9	45	25	2	1.00	0.75	19.82357
20	Cracklin' Oat Bran	K	cold	110	3	3	140	4	10	7	160	25	3	1.00	0.50	40.44877
59	Raisin Bran	K	cold	120	3	1	210	5	14	12	240	25	2	1.33	0.75	39.25920

Another example of the `subset()` function…

cereal |> 
  subset(sugars < 5 & type == "hot")

	name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
21	Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21	0	-1	0	2	1	1.00	64.53382
44	Maypo	A	hot	100	4	1	0	0.0	16	3	95	25	2	1	1.00	54.85092
58	Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1	-1	110	0	1	1	0.67	50.82839

`arrange()`

We arrange the rows of the data in order of a particular variable.

cereal |> 
  arrange(sodium)

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354

`arrange()`

We can arrange by multiple variables.

cereal |> 
  arrange(sodium, sugars) |>
  select(name, manuf, type, sodium, sugars)

name	manuf	type	sodium	sugars
Quaker Oatmeal	Q	hot	0	-1
Puffed Rice	Q	cold	0	0
Puffed Wheat	Q	cold	0	0
Shredded Wheat	N	cold	0	0
Shredded Wheat 'n'Bran	N	cold	0	0
Shredded Wheat spoon size	N	cold	0	0
Maypo	A	hot	0	3
Raisin Squares	K	cold	0	6
Frosted Mini-Wheats	K	cold	0	7
Strawberry Fruit Wheats	N	cold	15	5
100% Natural Bran	Q	cold	15	8
Golden Crisp	P	cold	45	15
Smacks	K	cold	70	15
Great Grains Pecan	P	cold	75	4
Cream of Wheat (Quick)	N	hot	80	0
Corn Pops	K	cold	90	12
Muesli Raisins; Dates; & Almonds	R	cold	95	11
Froot Loops	K	cold	125	13
Apple Jacks	K	cold	125	14
100% Bran	N	cold	130	6
Quaker Oat Squares	Q	cold	135	6
Fruity Pebbles	P	cold	135	12
All-Bran with Extra Fiber	K	cold	140	0
Grape Nuts Flakes	P	cold	140	5
Clusters	G	cold	140	7
Cracklin' Oat Bran	K	cold	140	7
Raisin Nut Bran	G	cold	140	8
Crispy Wheat & Raisins	G	cold	140	10
Trix	G	cold	140	12
Life	Q	cold	150	6
Muesli Raisins; Peaches; & Pecans	R	cold	150	11
Mueslix Crispy Blend	K	cold	150	13
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	160	10
Nutri-grain Wheat	K	cold	170	2
Grape-Nuts	P	cold	170	3
Just Right Crunchy Nuggets	K	cold	170	6
Just Right Fruit & Nut	K	cold	170	9
Oatmeal Raisin Crisp	G	cold	170	10
Apple Cinnamon Cheerios	G	cold	180	10
Honey-comb	P	cold	180	11
Lucky Charms	G	cold	180	12
Cocoa Puffs	G	cold	180	13
Count Chocula	G	cold	180	13
Double Chex	R	cold	190	5
Nut&Honey Crunch	K	cold	190	9
Total Raisin Bran	G	cold	190	14
Total Corn Flakes	G	cold	200	3
Total Whole Grain	G	cold	200	3
Wheaties	G	cold	200	3
Bran Chex	R	cold	200	6
Almond Delight	R	cold	200	8
Wheaties Honey Gold	G	cold	200	8
Frosted Flakes	K	cold	200	11
Post Nat. Raisin Bran	P	cold	200	14
Bran Flakes	P	cold	210	5
Basic 4	G	cold	210	8
Cinnamon Toast Crunch	G	cold	210	9
Raisin Bran	K	cold	210	12
Crispix	K	cold	220	3
Multi-Grain Cheerios	G	cold	220	6
Nutri-Grain Almond-Raisin	K	cold	220	7
Honey Graham Ohs	Q	cold	220	11
Cap'n'Crunch	Q	cold	220	12
Special K	K	cold	230	3
Wheat Chex	R	cold	230	3
Rice Chex	R	cold	240	2
Fruitful Bran	K	cold	240	12
Triples	G	cold	250	3
Honey Nut Cheerios	G	cold	250	10
Kix	G	cold	260	3
All-Bran	K	cold	260	5
Corn Chex	R	cold	280	3
Golden Grahams	G	cold	280	9
Cheerios	G	cold	290	1
Corn Flakes	K	cold	290	2
Rice Krispies	K	cold	290	3
Product 19	K	cold	320	3

`arrange()`: Descending Order

Default is ascending order…

…but can add desc() to get descending order!

cereal |> 
  arrange(desc(sodium))

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179

`slice_max()`

Selects the n rows with the maximum values of the specified variable.

cereal |> 
  slice_max(order_by = sugars, n = 3)

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
Golden Crisp	P	cold	100	2	0	45	0	11	15	40	25	1	1.00	0.88	35.25244
Smacks	K	cold	110	2	1	70	1	9	15	40	25	2	1.00	0.75	31.23005
Apple Jacks	K	cold	110	2	0	125	1	11	14	30	25	2	1.00	1.00	33.17409
Post Nat. Raisin Bran	P	cold	120	3	1	200	6	11	14	260	25	3	1.33	0.67	37.84059
Total Raisin Bran	G	cold	140	3	1	190	4	15	14	230	100	3	1.50	1.00	28.59278

Not interested in ties?

You can use the with_ties = FALSE argument to remove ties from your output!

How do we “arrange” in base `R`?

You can use the order() function!

cereal[order(cereal$sodium, cereal$sugars),]

	name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
58	Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
55	Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
56	Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
64	Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
65	Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
66	Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
44	Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
61	Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
27	Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
69	Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
2	100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
31	Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
67	Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
35	Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
21	Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
18	Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
45	Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
25	Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
7	Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
1	100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
57	Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
30	Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
4	All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
33	Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
14	Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
20	Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
60	Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
23	Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
74	Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
42	Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
46	Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
47	Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335
28	Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
51	Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
34	Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
39	Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
40	Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
52	Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
6	Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
38	Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
43	Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
15	Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
19	Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
24	Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
49	Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
71	Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
70	Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
72	Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
76	Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
9	Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
5	Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
77	Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756
26	Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
53	Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
10	Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
8	Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
13	Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
59	Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
22	Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
48	Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
50	Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
36	Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
11	Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
68	Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
75	Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
62	Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
29	Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
73	Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
37	Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
41	Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
3	All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
16	Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
32	Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
12	Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
17	Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
63	Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
54	Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354

`select()`

We select which variables (columns) we would like to remain in the data.

cereal |> 
  select(name, manuf, calories, cups)

name	manuf	calories	cups
100% Bran	N	70	0.33
100% Natural Bran	Q	120	1.00
All-Bran	K	70	0.33
All-Bran with Extra Fiber	K	50	0.50
Almond Delight	R	110	0.75
Apple Cinnamon Cheerios	G	110	0.75
Apple Jacks	K	110	1.00
Basic 4	G	130	0.75
Bran Chex	R	90	0.67
Bran Flakes	P	90	0.67
Cap'n'Crunch	Q	120	0.75
Cheerios	G	110	1.25
Cinnamon Toast Crunch	G	120	0.75
Clusters	G	110	0.50
Cocoa Puffs	G	110	1.00
Corn Chex	R	110	1.00
Corn Flakes	K	100	1.00
Corn Pops	K	110	1.00
Count Chocula	G	110	1.00
Cracklin' Oat Bran	K	110	0.50
Cream of Wheat (Quick)	N	100	1.00
Crispix	K	110	1.00
Crispy Wheat & Raisins	G	100	0.75
Double Chex	R	100	0.75
Froot Loops	K	110	1.00
Frosted Flakes	K	110	0.75
Frosted Mini-Wheats	K	100	0.80
Fruit & Fibre Dates; Walnuts; and Oats	P	120	0.67
Fruitful Bran	K	120	0.67
Fruity Pebbles	P	110	0.75
Golden Crisp	P	100	0.88
Golden Grahams	G	110	0.75
Grape Nuts Flakes	P	100	0.88
Grape-Nuts	P	110	0.25
Great Grains Pecan	P	120	0.33
Honey Graham Ohs	Q	120	1.00
Honey Nut Cheerios	G	110	0.75
Honey-comb	P	110	1.33
Just Right Crunchy Nuggets	K	110	1.00
Just Right Fruit & Nut	K	140	0.75
Kix	G	110	1.50
Life	Q	100	0.67
Lucky Charms	G	110	1.00
Maypo	A	100	1.00
Muesli Raisins; Dates; & Almonds	R	150	1.00
Muesli Raisins; Peaches; & Pecans	R	150	1.00
Mueslix Crispy Blend	K	160	0.67
Multi-Grain Cheerios	G	100	1.00
Nut&Honey Crunch	K	120	0.67
Nutri-Grain Almond-Raisin	K	140	0.67
Nutri-grain Wheat	K	90	1.00
Oatmeal Raisin Crisp	G	130	0.50
Post Nat. Raisin Bran	P	120	0.67
Product 19	K	100	1.00
Puffed Rice	Q	50	1.00
Puffed Wheat	Q	50	1.00
Quaker Oat Squares	Q	100	0.50
Quaker Oatmeal	Q	100	0.67
Raisin Bran	K	120	0.75
Raisin Nut Bran	G	100	0.50
Raisin Squares	K	90	0.50
Rice Chex	R	110	1.13
Rice Krispies	K	110	1.00
Shredded Wheat	N	80	1.00
Shredded Wheat 'n'Bran	N	90	0.67
Shredded Wheat spoon size	N	90	0.67
Smacks	K	110	0.75
Special K	K	110	1.00
Strawberry Fruit Wheats	N	90	1.00
Total Corn Flakes	G	110	1.00
Total Raisin Bran	G	140	1.00
Total Whole Grain	G	100	1.00
Triples	G	110	0.75
Trix	G	110	1.00
Wheat Chex	R	100	0.67
Wheaties	G	100	1.00
Wheaties Honey Gold	G	110	0.75

`select()` a Sequence of Columns

cereal |> 
  select(name:calories)

name	manuf	type	calories
100% Bran	N	cold	70
100% Natural Bran	Q	cold	120
All-Bran	K	cold	70
All-Bran with Extra Fiber	K	cold	50
Almond Delight	R	cold	110
Apple Cinnamon Cheerios	G	cold	110
Apple Jacks	K	cold	110
Basic 4	G	cold	130
Bran Chex	R	cold	90
Bran Flakes	P	cold	90
Cap'n'Crunch	Q	cold	120
Cheerios	G	cold	110
Cinnamon Toast Crunch	G	cold	120
Clusters	G	cold	110
Cocoa Puffs	G	cold	110
Corn Chex	R	cold	110
Corn Flakes	K	cold	100
Corn Pops	K	cold	110
Count Chocula	G	cold	110
Cracklin' Oat Bran	K	cold	110
Cream of Wheat (Quick)	N	hot	100
Crispix	K	cold	110
Crispy Wheat & Raisins	G	cold	100
Double Chex	R	cold	100
Froot Loops	K	cold	110
Frosted Flakes	K	cold	110
Frosted Mini-Wheats	K	cold	100
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120
Fruitful Bran	K	cold	120
Fruity Pebbles	P	cold	110
Golden Crisp	P	cold	100
Golden Grahams	G	cold	110
Grape Nuts Flakes	P	cold	100
Grape-Nuts	P	cold	110
Great Grains Pecan	P	cold	120
Honey Graham Ohs	Q	cold	120
Honey Nut Cheerios	G	cold	110
Honey-comb	P	cold	110
Just Right Crunchy Nuggets	K	cold	110
Just Right Fruit & Nut	K	cold	140
Kix	G	cold	110
Life	Q	cold	100
Lucky Charms	G	cold	110
Maypo	A	hot	100
Muesli Raisins; Dates; & Almonds	R	cold	150
Muesli Raisins; Peaches; & Pecans	R	cold	150
Mueslix Crispy Blend	K	cold	160
Multi-Grain Cheerios	G	cold	100
Nut&Honey Crunch	K	cold	120
Nutri-Grain Almond-Raisin	K	cold	140
Nutri-grain Wheat	K	cold	90
Oatmeal Raisin Crisp	G	cold	130
Post Nat. Raisin Bran	P	cold	120
Product 19	K	cold	100
Puffed Rice	Q	cold	50
Puffed Wheat	Q	cold	50
Quaker Oat Squares	Q	cold	100
Quaker Oatmeal	Q	hot	100
Raisin Bran	K	cold	120
Raisin Nut Bran	G	cold	100
Raisin Squares	K	cold	90
Rice Chex	R	cold	110
Rice Krispies	K	cold	110
Shredded Wheat	N	cold	80
Shredded Wheat 'n'Bran	N	cold	90
Shredded Wheat spoon size	N	cold	90
Smacks	K	cold	110
Special K	K	cold	110
Strawberry Fruit Wheats	N	cold	90
Total Corn Flakes	G	cold	110
Total Raisin Bran	G	cold	140
Total Whole Grain	G	cold	100
Triples	G	cold	110
Trix	G	cold	110
Wheat Chex	R	cold	100
Wheaties	G	cold	100
Wheaties Honey Gold	G	cold	110

Remove Columns

cereal |> 
  select(-rating)

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75

`select()`: Reordering

You can reorder columns inside of select().

cereal |> 
  select(name, rating, manuf, type, 
         calories, cups, weight,
         everything()
         )

name	rating	manuf	type	calories	cups	weight	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf
100% Bran	68.40297	N	cold	70	0.33	1.00	4	1	130	10.0	5.0	6	280	25	3
100% Natural Bran	33.98368	Q	cold	120	1.00	1.00	3	5	15	2.0	8.0	8	135	0	3
All-Bran	59.42551	K	cold	70	0.33	1.00	4	1	260	9.0	7.0	5	320	25	3
All-Bran with Extra Fiber	93.70491	K	cold	50	0.50	1.00	4	0	140	14.0	8.0	0	330	25	3
Almond Delight	34.38484	R	cold	110	0.75	1.00	2	2	200	1.0	14.0	8	-1	25	3
Apple Cinnamon Cheerios	29.50954	G	cold	110	0.75	1.00	2	2	180	1.5	10.5	10	70	25	1
Apple Jacks	33.17409	K	cold	110	1.00	1.00	2	0	125	1.0	11.0	14	30	25	2
Basic 4	37.03856	G	cold	130	0.75	1.33	3	2	210	2.0	18.0	8	100	25	3
Bran Chex	49.12025	R	cold	90	0.67	1.00	2	1	200	4.0	15.0	6	125	25	1
Bran Flakes	53.31381	P	cold	90	0.67	1.00	3	0	210	5.0	13.0	5	190	25	3
Cap'n'Crunch	18.04285	Q	cold	120	0.75	1.00	1	2	220	0.0	12.0	12	35	25	2
Cheerios	50.76500	G	cold	110	1.25	1.00	6	2	290	2.0	17.0	1	105	25	1
Cinnamon Toast Crunch	19.82357	G	cold	120	0.75	1.00	1	3	210	0.0	13.0	9	45	25	2
Clusters	40.40021	G	cold	110	0.50	1.00	3	2	140	2.0	13.0	7	105	25	3
Cocoa Puffs	22.73645	G	cold	110	1.00	1.00	1	1	180	0.0	12.0	13	55	25	2
Corn Chex	41.44502	R	cold	110	1.00	1.00	2	0	280	0.0	22.0	3	25	25	1
Corn Flakes	45.86332	K	cold	100	1.00	1.00	2	0	290	1.0	21.0	2	35	25	1
Corn Pops	35.78279	K	cold	110	1.00	1.00	1	0	90	1.0	13.0	12	20	25	2
Count Chocula	22.39651	G	cold	110	1.00	1.00	1	1	180	0.0	12.0	13	65	25	2
Cracklin' Oat Bran	40.44877	K	cold	110	0.50	1.00	3	3	140	4.0	10.0	7	160	25	3
Cream of Wheat (Quick)	64.53382	N	hot	100	1.00	1.00	3	0	80	1.0	21.0	0	-1	0	2
Crispix	46.89564	K	cold	110	1.00	1.00	2	0	220	1.0	21.0	3	30	25	3
Crispy Wheat & Raisins	36.17620	G	cold	100	0.75	1.00	2	1	140	2.0	11.0	10	120	25	3
Double Chex	44.33086	R	cold	100	0.75	1.00	2	0	190	1.0	18.0	5	80	25	3
Froot Loops	32.20758	K	cold	110	1.00	1.00	2	1	125	1.0	11.0	13	30	25	2
Frosted Flakes	31.43597	K	cold	110	0.75	1.00	1	0	200	1.0	14.0	11	25	25	1
Frosted Mini-Wheats	58.34514	K	cold	100	0.80	1.00	3	0	0	3.0	14.0	7	100	25	2
Fruit & Fibre Dates; Walnuts; and Oats	40.91705	P	cold	120	0.67	1.25	3	2	160	5.0	12.0	10	200	25	3
Fruitful Bran	41.01549	K	cold	120	0.67	1.33	3	0	240	5.0	14.0	12	190	25	3
Fruity Pebbles	28.02576	P	cold	110	0.75	1.00	1	1	135	0.0	13.0	12	25	25	2
Golden Crisp	35.25244	P	cold	100	0.88	1.00	2	0	45	0.0	11.0	15	40	25	1
Golden Grahams	23.80404	G	cold	110	0.75	1.00	1	1	280	0.0	15.0	9	45	25	2
Grape Nuts Flakes	52.07690	P	cold	100	0.88	1.00	3	1	140	3.0	15.0	5	85	25	3
Grape-Nuts	53.37101	P	cold	110	0.25	1.00	3	0	170	3.0	17.0	3	90	25	3
Great Grains Pecan	45.81172	P	cold	120	0.33	1.00	3	3	75	3.0	13.0	4	100	25	3
Honey Graham Ohs	21.87129	Q	cold	120	1.00	1.00	1	2	220	1.0	12.0	11	45	25	2
Honey Nut Cheerios	31.07222	G	cold	110	0.75	1.00	3	1	250	1.5	11.5	10	90	25	1
Honey-comb	28.74241	P	cold	110	1.33	1.00	1	0	180	0.0	14.0	11	35	25	1
Just Right Crunchy Nuggets	36.52368	K	cold	110	1.00	1.00	2	1	170	1.0	17.0	6	60	100	3
Just Right Fruit & Nut	36.47151	K	cold	140	0.75	1.30	3	1	170	2.0	20.0	9	95	100	3
Kix	39.24111	G	cold	110	1.50	1.00	2	1	260	0.0	21.0	3	40	25	2
Life	45.32807	Q	cold	100	0.67	1.00	4	2	150	2.0	12.0	6	95	25	2
Lucky Charms	26.73451	G	cold	110	1.00	1.00	2	1	180	0.0	12.0	12	55	25	2
Maypo	54.85092	A	hot	100	1.00	1.00	4	1	0	0.0	16.0	3	95	25	2
Muesli Raisins; Dates; & Almonds	37.13686	R	cold	150	1.00	1.00	4	3	95	3.0	16.0	11	170	25	3
Muesli Raisins; Peaches; & Pecans	34.13976	R	cold	150	1.00	1.00	4	3	150	3.0	16.0	11	170	25	3
Mueslix Crispy Blend	30.31335	K	cold	160	0.67	1.50	3	2	150	3.0	17.0	13	160	25	3
Multi-Grain Cheerios	40.10596	G	cold	100	1.00	1.00	2	1	220	2.0	15.0	6	90	25	1
Nut&Honey Crunch	29.92429	K	cold	120	0.67	1.00	2	1	190	0.0	15.0	9	40	25	2
Nutri-Grain Almond-Raisin	40.69232	K	cold	140	0.67	1.33	3	2	220	3.0	21.0	7	130	25	3
Nutri-grain Wheat	59.64284	K	cold	90	1.00	1.00	3	0	170	3.0	18.0	2	90	25	3
Oatmeal Raisin Crisp	30.45084	G	cold	130	0.50	1.25	3	2	170	1.5	13.5	10	120	25	3
Post Nat. Raisin Bran	37.84059	P	cold	120	0.67	1.33	3	1	200	6.0	11.0	14	260	25	3
Product 19	41.50354	K	cold	100	1.00	1.00	3	0	320	1.0	20.0	3	45	100	3
Puffed Rice	60.75611	Q	cold	50	1.00	0.50	1	0	0	0.0	13.0	0	15	0	3
Puffed Wheat	63.00565	Q	cold	50	1.00	0.50	2	0	0	1.0	10.0	0	50	0	3
Quaker Oat Squares	49.51187	Q	cold	100	0.50	1.00	4	1	135	2.0	14.0	6	110	25	3
Quaker Oatmeal	50.82839	Q	hot	100	0.67	1.00	5	2	0	2.7	-1.0	-1	110	0	1
Raisin Bran	39.25920	K	cold	120	0.75	1.33	3	1	210	5.0	14.0	12	240	25	2
Raisin Nut Bran	39.70340	G	cold	100	0.50	1.00	3	2	140	2.5	10.5	8	140	25	3
Raisin Squares	55.33314	K	cold	90	0.50	1.00	2	0	0	2.0	15.0	6	110	25	3
Rice Chex	41.99893	R	cold	110	1.13	1.00	1	0	240	0.0	23.0	2	30	25	1
Rice Krispies	40.56016	K	cold	110	1.00	1.00	2	0	290	0.0	22.0	3	35	25	1
Shredded Wheat	68.23588	N	cold	80	1.00	0.83	2	0	0	3.0	16.0	0	95	0	1
Shredded Wheat 'n'Bran	74.47295	N	cold	90	0.67	1.00	3	0	0	4.0	19.0	0	140	0	1
Shredded Wheat spoon size	72.80179	N	cold	90	0.67	1.00	3	0	0	3.0	20.0	0	120	0	1
Smacks	31.23005	K	cold	110	0.75	1.00	2	1	70	1.0	9.0	15	40	25	2
Special K	53.13132	K	cold	110	1.00	1.00	6	0	230	1.0	16.0	3	55	25	1
Strawberry Fruit Wheats	59.36399	N	cold	90	1.00	1.00	2	0	15	3.0	15.0	5	90	25	2
Total Corn Flakes	38.83975	G	cold	110	1.00	1.00	2	1	200	0.0	21.0	3	35	100	3
Total Raisin Bran	28.59278	G	cold	140	1.00	1.50	3	1	190	4.0	15.0	14	230	100	3
Total Whole Grain	46.65884	G	cold	100	1.00	1.00	3	1	200	3.0	16.0	3	110	100	3
Triples	39.10617	G	cold	110	0.75	1.00	2	1	250	0.0	21.0	3	60	25	3
Trix	27.75330	G	cold	110	1.00	1.00	1	1	140	0.0	13.0	12	25	25	2
Wheat Chex	49.78744	R	cold	100	0.67	1.00	3	1	230	3.0	17.0	3	115	25	1
Wheaties	51.59219	G	cold	100	1.00	1.00	3	1	200	3.0	17.0	3	110	25	1
Wheaties Honey Gold	36.18756	G	cold	110	0.75	1.00	2	1	200	1.0	16.0	8	60	25	1

`select()`: Handy Helpers!

everything() : selects all columns that you have not already specified
starts_with() : selects columns with names that start with the specified string
ends_with() : selects columns with names that end with the specified string
contains() : selects columns with names that contain the specified string

Strings in Week 5

You’ll learn more about working with strings in Week 5!

How do we “select” in base `R`?

You can use bracketing ([]) or the subset() function!

cereal[ , c("name", 
            "manuf", 
            "calories", 
            "cups")]

subset(cereal, 
       select = c(name, 
                  manuf, 
                  calories, 
                  cups)
       )

name	manuf	calories	cups
100% Bran	N	70	0.33
100% Natural Bran	Q	120	1.00
All-Bran	K	70	0.33
All-Bran with Extra Fiber	K	50	0.50
Almond Delight	R	110	0.75
Apple Cinnamon Cheerios	G	110	0.75
Apple Jacks	K	110	1.00
Basic 4	G	130	0.75
Bran Chex	R	90	0.67
Bran Flakes	P	90	0.67
Cap'n'Crunch	Q	120	0.75
Cheerios	G	110	1.25
Cinnamon Toast Crunch	G	120	0.75
Clusters	G	110	0.50
Cocoa Puffs	G	110	1.00
Corn Chex	R	110	1.00
Corn Flakes	K	100	1.00
Corn Pops	K	110	1.00
Count Chocula	G	110	1.00
Cracklin' Oat Bran	K	110	0.50
Cream of Wheat (Quick)	N	100	1.00
Crispix	K	110	1.00
Crispy Wheat & Raisins	G	100	0.75
Double Chex	R	100	0.75
Froot Loops	K	110	1.00
Frosted Flakes	K	110	0.75
Frosted Mini-Wheats	K	100	0.80
Fruit & Fibre Dates; Walnuts; and Oats	P	120	0.67
Fruitful Bran	K	120	0.67
Fruity Pebbles	P	110	0.75
Golden Crisp	P	100	0.88
Golden Grahams	G	110	0.75
Grape Nuts Flakes	P	100	0.88
Grape-Nuts	P	110	0.25
Great Grains Pecan	P	120	0.33
Honey Graham Ohs	Q	120	1.00
Honey Nut Cheerios	G	110	0.75
Honey-comb	P	110	1.33
Just Right Crunchy Nuggets	K	110	1.00
Just Right Fruit & Nut	K	140	0.75
Kix	G	110	1.50
Life	Q	100	0.67
Lucky Charms	G	110	1.00
Maypo	A	100	1.00
Muesli Raisins; Dates; & Almonds	R	150	1.00
Muesli Raisins; Peaches; & Pecans	R	150	1.00
Mueslix Crispy Blend	K	160	0.67
Multi-Grain Cheerios	G	100	1.00
Nut&Honey Crunch	K	120	0.67
Nutri-Grain Almond-Raisin	K	140	0.67
Nutri-grain Wheat	K	90	1.00
Oatmeal Raisin Crisp	G	130	0.50
Post Nat. Raisin Bran	P	120	0.67
Product 19	K	100	1.00
Puffed Rice	Q	50	1.00
Puffed Wheat	Q	50	1.00
Quaker Oat Squares	Q	100	0.50
Quaker Oatmeal	Q	100	0.67
Raisin Bran	K	120	0.75
Raisin Nut Bran	G	100	0.50
Raisin Squares	K	90	0.50
Rice Chex	R	110	1.13
Rice Krispies	K	110	1.00
Shredded Wheat	N	80	1.00
Shredded Wheat 'n'Bran	N	90	0.67
Shredded Wheat spoon size	N	90	0.67
Smacks	K	110	0.75
Special K	K	110	1.00
Strawberry Fruit Wheats	N	90	1.00
Total Corn Flakes	G	110	1.00
Total Raisin Bran	G	140	1.00
Total Whole Grain	G	100	1.00
Triples	G	110	0.75
Trix	G	110	1.00
Wheat Chex	R	100	0.67
Wheaties	G	100	1.00
Wheaties Honey Gold	G	110	0.75

`rename()`

You can rename columns with select(), but all columns not specified will be dropped.
- Using the rename() function is easier!

cereal |> 
  rename(temp = type)

name	manuf	temp	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756

`mutate()`

A cartoon illustration of a scientist holding a glowing test tube, from which several hexagonal shapes are emerging and transforming as they float upward. The scientist, dressed in a lab coat and safety goggles, symbolizes the concept of mutation, representing the 'mutate()' function from the 'dplyr' package in R. This function is used to modify or create new variables in a dataset, depicted here as hexagonal shapes changing form.

Artwork by Allison Horst

`mutate()` to include a new variable

cereal |> 
  mutate(potass_per_cup = potass / cups)

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating	potass_per_cup
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297	848.484848
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368	135.000000
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551	969.696970
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491	660.000000
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484	-1.333333
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954	93.333333
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409	30.000000
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856	133.333333
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025	186.567164
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381	283.582090
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285	46.666667
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500	84.000000
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357	60.000000
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021	210.000000
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645	55.000000
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502	25.000000
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332	35.000000
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279	20.000000
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651	65.000000
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877	320.000000
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382	-1.000000
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564	30.000000
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620	160.000000
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086	106.666667
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758	30.000000
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597	33.333333
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514	125.000000
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705	298.507463
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549	283.582090
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576	33.333333
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244	45.454546
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404	60.000000
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690	96.590909
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101	360.000000
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172	303.030303
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129	45.000000
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222	120.000000
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241	26.315790
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368	60.000000
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151	126.666667
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111	26.666667
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807	141.791045
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451	55.000000
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092	95.000000
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686	170.000000
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976	170.000000
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335	238.805970
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596	90.000000
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429	59.701493
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232	194.029851
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284	90.000000
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084	240.000000
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059	388.059702
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354	45.000000
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611	15.000000
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565	50.000000
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187	220.000000
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839	164.179104
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920	320.000000
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340	280.000000
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314	220.000000
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893	26.548673
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016	35.000000
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588	95.000000
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295	208.955224
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179	179.104478
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005	53.333333
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132	55.000000
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399	90.000000
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975	35.000000
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278	230.000000
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884	110.000000
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617	80.000000
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330	25.000000
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744	171.641791
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219	110.000000
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756	80.000000

`mutate()` to change an existing variable

cereal |> 
  mutate(shelf = as.factor(shelf))

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756

`mutate()`: Handy Helpers!

as.factor(), as.numeric(), etc. : change variable type
+, -, *, / : basic mathematical operations
%% : modulo (returns the remainder when doing division)

On Thursday we’ll talk about:

if_else(): creating a new variable with two levels
case_when(): creating a new variable with three or more levels

How do we “mutate” in base `R`?

You can define new columns…

cereal$potass_per_cup <- cereal$potass / cereal$cups

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating	potass_per_cup
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297	848.484848
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368	135.000000
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551	969.696970
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491	660.000000
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484	-1.333333
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954	93.333333
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409	30.000000
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856	133.333333
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025	186.567164
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381	283.582090
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285	46.666667
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500	84.000000
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357	60.000000
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021	210.000000
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645	55.000000
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502	25.000000
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332	35.000000
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279	20.000000
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651	65.000000
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877	320.000000
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382	-1.000000
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564	30.000000
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620	160.000000
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086	106.666667
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758	30.000000
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597	33.333333
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514	125.000000
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705	298.507463
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549	283.582090
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576	33.333333
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244	45.454546
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404	60.000000
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690	96.590909
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101	360.000000
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172	303.030303
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129	45.000000
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222	120.000000
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241	26.315790
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368	60.000000
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151	126.666667
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111	26.666667
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807	141.791045
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451	55.000000
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092	95.000000
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686	170.000000
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976	170.000000
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335	238.805970
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596	90.000000
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429	59.701493
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232	194.029851
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284	90.000000
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084	240.000000
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059	388.059702
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354	45.000000
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611	15.000000
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565	50.000000
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187	220.000000
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839	164.179104
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920	320.000000
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340	280.000000
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314	220.000000
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893	26.548673
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016	35.000000
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588	95.000000
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295	208.955224
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179	179.104478
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005	53.333333
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132	55.000000
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399	90.000000
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975	35.000000
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278	230.000000
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884	110.000000
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617	80.000000
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330	25.000000
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744	171.641791
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219	110.000000
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756	80.000000

…OR overwrite old ones!

cereal$shelf <- as.factor(cereal$shelf)

`group_by()`

A cartoon illustration of a group of animals, including a horse, a cow, a sheep, and a chicken, standing closely together inside a lasso. The lasso represents grouping, and the animals appear calm and organized. Outside the lasso, there is an open space, suggesting the concept of 'ungrouping' in data manipulation, where the grouping is removed and entities are no longer confined to the same category or structure. This represents the 'ungroup()' function in R's dplyr package, symbolizing the removal of grouping from data.

Artwork by Allison Horst

`group_by()`

Separate the data into different groups based on a categorical variable.

The data gets grouped, but nothing happens externally.

cereal |> 
  group_by(type)

# A tibble: 77 × 16
# Groups:   type [2]
   name      manuf type  calories protein   fat sodium fiber carbo sugars potass
   <fct>     <fct> <fct>    <int>   <int> <int>  <int> <dbl> <dbl>  <int>  <int>
 1 100% Bran N     cold        70       4     1    130  10     5        6    280
 2 100% Nat… Q     cold       120       3     5     15   2     8        8    135
 3 All-Bran  K     cold        70       4     1    260   9     7        5    320
 4 All-Bran… K     cold        50       4     0    140  14     8        0    330
 5 Almond D… R     cold       110       2     2    200   1    14        8     -1
 6 Apple Ci… G     cold       110       2     2    180   1.5  10.5     10     70
 7 Apple Ja… K     cold       110       2     0    125   1    11       14     30
 8 Basic 4   G     cold       130       3     2    210   2    18        8    100
 9 Bran Chex R     cold        90       2     1    200   4    15        6    125
10 Bran Fla… P     cold        90       3     0    210   5    13        5    190
# ℹ 67 more rows
# ℹ 5 more variables: vitamins <int>, shelf <int>, weight <dbl>, cups <dbl>,
#   rating <dbl>

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756

`summarize()`

group_by() is almost always paired with summarize()!

`summarize()`

We can calculate summaries of variables in the data.

cereal |> 
  summarise(mean_fiber = mean(fiber))

  mean_fiber
1   2.151948

Or multiple summaries at the same time.

cereal |> 
summarize(mean_fiber = mean(fiber),
          num_cereals = n(),
          mean_sugar = mean(sugars)
          )

  mean_fiber num_cereals mean_sugar
1   2.151948          77   6.922078

`summarize()`: Handy Helpers!

mean(), median(), sd(), sum()
min(), max()
n(), n_distinct() : counts the number of (distinct) elements
first(), last(), nth() : extract the first, last, or nth element

`group_by() + summarize()`!

group_by a variable (or multiple variables)
summarize a variable (or multiple variables) within the groups

cereal |> 
  group_by(manuf) |> 
  summarise(mean_sugar = mean(sugars))

manuf	mean_sugar
A	3.000000
G	7.954546
K	7.565217
N	1.833333
P	8.777778
Q	5.250000
R	6.125000

`group_by() + mutate()`!

group_by a variable (or multiple variables)
mutate a variable (or multiple variables) within the groups

cereal |> 
  group_by(manuf) |> 
  mutate(mean_sugar = mean(sugars))

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating	mean_sugar
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297	1.833333
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368	5.250000
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551	7.565217
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491	7.565217
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484	6.125000
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954	7.954546
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409	7.565217
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856	7.954546
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025	6.125000
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381	8.777778
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285	5.250000
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500	7.954546
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357	7.954546
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021	7.954546
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645	7.954546
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502	6.125000
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332	7.565217
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279	7.565217
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651	7.954546
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877	7.565217
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382	1.833333
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564	7.565217
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620	7.954546
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086	6.125000
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758	7.565217
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597	7.565217
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514	7.565217
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705	8.777778
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549	7.565217
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576	8.777778
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244	8.777778
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404	7.954546
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690	8.777778
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101	8.777778
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172	8.777778
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129	5.250000
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222	7.954546
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241	8.777778
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368	7.565217
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151	7.565217
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111	7.954546
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807	5.250000
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451	7.954546
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092	3.000000
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686	6.125000
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976	6.125000
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335	7.565217
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596	7.954546
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429	7.565217
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232	7.565217
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284	7.565217
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084	7.954546
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059	8.777778
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354	7.565217
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611	5.250000
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565	5.250000
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187	5.250000
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839	5.250000
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920	7.565217
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340	7.954546
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314	7.565217
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893	6.125000
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016	7.565217
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588	1.833333
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295	1.833333
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179	1.833333
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005	7.565217
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132	7.565217
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399	1.833333
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975	7.954546
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278	7.954546
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884	7.954546
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617	7.954546
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330	7.954546
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744	6.125000
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219	7.954546
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756	7.954546

The Difference?

group_by() + summarize() collapses the data.

You will only have one row per group remaining.

group_by() + mutate() does not.

You will have the full number of rows remaining.

`ungroup()`

The ungroup() function will remove the internal grouping in your data.

This is not something that you always need to do, but if you are getting unexpected output downstream from a group_by() statement, try ungrouping your data!

When would you need to `ungroup()`?

The default for summarize() is to drop the last variable after the subsequent operation is taken.

Meaning, the first variables used for grouping will not be dropped, unless otherwise specified.

cereal |> 
  group_by(manuf, type) |> 
  summarize(mean_calories = mean(calories))

# A tibble: 9 × 3
# Groups:   manuf [7]
  manuf type  mean_calories
  <fct> <fct>         <dbl>
1 A     hot           100  
2 G     cold          111. 
3 K     cold          109. 
4 N     cold           84  
5 N     hot           100  
6 P     cold          109. 
7 Q     cold           94.3
8 Q     hot           100  
9 R     cold          115

How do I ungroup?

Option 1 - Use the .groups argument of summarize()

cereal |> 
  group_by(manuf, type) |> 
  summarize(mean_calories = mean(calories), 
            .groups = "drop")

Option 2 - Use the ungroup() function after summarize()

cereal |> 
  group_by(manuf, type) |> 
  summarize(mean_calories = mean(calories)) |> 
  ungroup()

How do we “group” and “summarize” in base `R`?

You can use the aggregate() function.

cereal |> 
  aggregate(sugars ~ manuf, FUN = mean)

manuf	sugars
A	3.000000
G	7.954546
K	7.565217
N	1.833333
P	8.777778
Q	5.250000
R	6.125000

Glue it all together!

cereal |> 
  filter(type == "cold") |> 
  mutate(potass_per_cup = potass / cups) |> 
  group_by(manuf) |> 
  summarise(mean_potass_per_cup = mean(potass_per_cup))

manuf	mean_potass_per_cup
G	109.1970
K	175.3978
N	284.3089
P	203.8749
Q	93.3511
R	106.8864

Code Formatting

Similar to the + formatting in ggplot, do not continue a line after writing a |>!

Bad Practice
Good
Amazing

cereal |> group_by(type) |> summarise(mean_fiber = mean(fiber), num_cereals = n(), mean_sugar = mean(sugars))

cereal |> 
  group_by(type) |> 
  summarise(mean_fiber = mean(fiber), num_cereals = n(), mean_sugar = mean(sugars))

cereal |> 
  group_by(type) |> 
  summarise(mean_fiber = mean(fiber), 
            num_cereals = n(),
            mean_sugar = mean(sugars)
            )

PA 3: Identify the Mystery College

Today you will use the dplyr package to clean some data and then use that cleaned data to figure out what college Ephelia has been accepted to.

A picture of a college building covered in green ivy. The building is reminescent of gothic architecture, with a brick exterior and many windows.

Finding Ephelia’s College

This activity will require knowledge of:

debugging code errors
function syntax
logical comparisons
dplyr verbs and when to use them
chaining steps together with the pipe operator

None of us have all these abilities. Each of us has some of these abilities.

dplyr Resources

Every group should have a dplyr cheatsheet!

On the Front

Column 1: grouped summaries (group_by() + summarize())
Column 2: filter()ing values with logical comparisons
Column 3: select()ing and mutate()ing variables

On the Back

Column 2: summary functions you might like to use with summarize()

A picture of the dplyr cheatsheet, which contains helpful information on working with data in a variety of ways.

Task Card

Every group should have a task card!

On the Front

the expectations of each role
the norms of collaborating

On the Back

advice for dealing with code errors
guidelines for formatting dplyr code

Pair Programming Expectations

During your collaboration, you and your partner will alternate between two roles:

Developer

Reads prompt and ensures Coder understands what is being asked.
Types the code specified by the Coder into the Quarto document.
Runs the code provided by the Coder.
Works with Coder to debug the code.
Evaluates the output.
Works with Coder to write code comments.

Coder

Reads out instructions or prompts
Directs the Developer what to type.
Talks with Developer about their ideas.
Manages resources (e.g., cheatsheets, textbook, slides).
Works with Developer to debug the code.
Works with Developer to write code comments.

How does this look in Posit Cloud?

First, both of you will do the following:

Join your Practice Activity workspace in Posit Cloud
- If you were sent a new email, you were added to a different group!
Log-in to Posit Cloud
Open the PA 3: Identify the Mystery College project
Open the PA3-dplyr.qmd file

Then, the partner whose birthday is closest to January 1st starts as the Developer (typing and listening to instructions from the Coder)!

The Coder does not type.
- The collaborative editing feature should allow you to track what is being typed.
The Developer only types what they are told to type.

Why are we switching?

Throughout the activity you will swap roles—the Developer will become the Coder, and the Coder will become the Developer.

We are alternating roles so everyone:

has the chance to apply their coding skills
practices talking through their code
has the opportunity to explain their thinking

External Resources

During the Practice Activity, you are not permitted to use Google or ChatGPT for help.

You are permitted to use:

the dplyr cheatsheet,
the course textbook, and
the course slides.

Submission

Submit the full name of the college Ephelia will attend to the Canvas Quiz.

Each person will input the full name of the college in the PA3 Canvas quiz.
The person who last occupied the role of Developer will download and submit the PA-3.html file for the group.
- Only one submission per group!

Data Wrangling with dplyr

Tuesday, October 8

Data Wrangling with dplyr

dplyr

dplyr verbs

The Pipe Operator

The Pipe Operator

The Pipe Operator

The Pipe Operator

Data Comes First!

I ❤️ |>

Example Data set – Cereal

filter()

filter()

filter()

Why not use &?

filter(): Handy Helpers!

filter(): |

filter(): %in%

filter(): Related Functions

How do we “filter” in base R?

Another example of the subset() function…

arrange()

arrange()

arrange()

arrange(): Descending Order

arrange(): Related Functions

slice_max()

How do we “arrange” in base R?

select()

select()

select() a Sequence of Columns

Remove Columns

select(): Reordering

select(): Handy Helpers!

How do we “select” in base R?

rename()

rename()

mutate()

mutate() to include a new variable

mutate() to change an existing variable

mutate(): Handy Helpers!

How do we “mutate” in base R?

group_by()

group_by()

summarize()

summarize()

summarize(): Handy Helpers!

group_by() + summarize()!

group_by() + mutate()!

The Difference?

ungroup()

When would you need to ungroup()?

How do I ungroup?

How do we “group” and “summarize” in base R?

Glue it all together!

Code Formatting

PA 3: Identify the Mystery College

Finding Ephelia’s College

dplyr Resources

Task Card

Pair Programming Expectations

How does this look in Posit Cloud?

Why are we switching?

External Resources

Submission

Exit Ticket

Data Wrangling with `dplyr`

`dplyr`

`dplyr` verbs

`filter()`

`filter()`

`filter()`

Why not use `&`?

`filter()`: Handy Helpers!

`filter()`: `|`

`filter()`: `%in%`

`filter()`: Related Functions

How do we “filter” in base `R`?

Another example of the `subset()` function…

`arrange()`

`arrange()`

`arrange()`

`arrange()`: Descending Order

`arrange()`: Related Functions

`slice_max()`

How do we “arrange” in base `R`?

`select()`

`select()`

`select()` a Sequence of Columns

`select()`: Reordering

`select()`: Handy Helpers!

How do we “select” in base `R`?

`rename()`

`rename()`

`mutate()`

`mutate()` to include a new variable

`mutate()` to change an existing variable

`mutate()`: Handy Helpers!

How do we “mutate” in base `R`?

`group_by()`

`group_by()`

`summarize()`

`summarize()`

`summarize()`: Handy Helpers!

`group_by() + summarize()`!

`group_by() + mutate()`!

`ungroup()`

When would you need to `ungroup()`?

How do we “group” and “summarize” in base `R`?