GitHub - tidyverse/dplyr: dplyr: A grammar of data manipulation (original) (raw)
dplyr 
Overview
dplyr is a grammar of data manipulation, providing a consistent set of verbs that help you solve the most common data manipulation challenges:
mutate()
adds new variables that are functions of existing variablesselect()
picks variables based on their names.filter()
picks cases based on their values.summarise()
reduces multiple values down to a single summary.arrange()
changes the ordering of the rows.
These all combine naturally with group_by()
which allows you to perform any operation “by group”. You can learn more about them invignette("dplyr")
. As well as these single-table verbs, dplyr also provides a variety of two-table verbs, which you can learn about invignette("two-table")
.
If you are new to dplyr, the best place to start is the data transformation chapter in R for Data Science.
Backends
In addition to data frames/tibbles, dplyr makes working with other computational backends accessible and efficient. Below is a list of alternative backends:
- arrow for larger-than-memory datasets, including on remote cloud storage like AWS S3, using the Apache Arrow C++ engine,Acero.
- dtplyr for large, in-memory datasets. Translates your dplyr code to high performancedata.table code.
- dbplyr for data stored in a relational database. Translates your dplyr code to SQL.
- duckplyr for usingduckdb on large, in-memory datasets with zero extra copies. Translates your dplyr code to high performance duckdb queries with an automatic R fallback when translation isn’t possible.
- duckdb for large datasets that are still small enough to fit on your computer.
- sparklyr for very large datasets stored in Apache Spark.
Installation
The easiest way to get dplyr is to install the whole tidyverse:
install.packages("tidyverse")
Alternatively, install just dplyr:
install.packages("dplyr")
Development version
To get a bug fix or to use a feature from the development version, you can install the development version of dplyr from GitHub.
install.packages("pak")
pak::pak("tidyverse/dplyr")
Cheat Sheet
Usage
library(dplyr)
starwars %>%
filter(species == "Droid")
#> # A tibble: 6 × 14
#> name height mass hair_color skin_color eye_color birth_year sex gender
#>
#> 1 C-3PO 167 75 gold yellow 112 none masculi…
#> 2 R2-D2 96 32 white, blue red 33 none masculi…
#> 3 R5-D4 97 32 white, red red NA none masculi…
#> 4 IG-88 200 140 none metal red 15 none masculi…
#> 5 R4-P17 96 NA none silver, red red, blue NA none feminine
#> # ℹ 1 more row
#> # ℹ 5 more variables: homeworld , species , films ,
#> # vehicles , starships
starwars %>%
select(name, ends_with("color"))
#> # A tibble: 87 × 4
#> name hair_color skin_color eye_color
#>
#> 1 Luke Skywalker blond fair blue
#> 2 C-3PO gold yellow
#> 3 R2-D2 white, blue red
#> 4 Darth Vader none white yellow
#> 5 Leia Organa brown light brown
#> # ℹ 82 more rows
starwars %>% mutate(name, bmi = mass / ((height / 100) ^ 2)) %>% select(name:mass, bmi) #> # A tibble: 87 × 4 #> name height mass bmi #> #> 1 Luke Skywalker 172 77 26.0 #> 2 C-3PO 167 75 26.9 #> 3 R2-D2 96 32 34.7 #> 4 Darth Vader 202 136 33.3 #> 5 Leia Organa 150 49 21.8 #> # ℹ 82 more rows
starwars %>% arrange(desc(mass)) #> # A tibble: 87 × 14 #> name height mass hair_color skin_color eye_color birth_year sex gender #> #> 1 Jabba De… 175 1358 green-tan… orange 600 herm… mascu… #> 2 Grievous 216 159 none brown, wh… green, y… NA male mascu… #> 3 IG-88 200 140 none metal red 15 none mascu… #> 4 Darth Va… 202 136 none white yellow 41.9 male mascu… #> 5 Tarfful 234 136 brown brown blue NA male mascu… #> # ℹ 82 more rows #> # ℹ 5 more variables: homeworld , species , films , #> # vehicles , starships
starwars %>%
group_by(species) %>%
summarise(
n = n(),
mass = mean(mass, na.rm = TRUE)
) %>%
filter(
n > 1,
mass > 50
)
#> # A tibble: 9 × 3
#> species n mass
#>
#> 1 Droid 6 69.8
#> 2 Gungan 3 74
#> 3 Human 35 81.3
#> 4 Kaminoan 2 88
#> 5 Mirialan 2 53.1
#> # ℹ 4 more rows
Getting help
If you encounter a clear bug, please file an issue with a minimal reproducible example onGitHub. For questions and other discussion, please use forum.posit.co.
Code of conduct
Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.