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https://github.com/rlesur/casewhen
Create reusable dplyr::case_when() functions
https://github.com/rlesur/casewhen
dbi dbplyr dplyr r reusable-functions rstats tidyverse
Last synced: 3 days ago
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Create reusable dplyr::case_when() functions
- Host: GitHub
- URL: https://github.com/rlesur/casewhen
- Owner: RLesur
- License: mit
- Created: 2018-04-24T22:11:36.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2018-05-16T20:13:37.000Z (over 6 years ago)
- Last Synced: 2024-07-31T19:28:54.950Z (4 months ago)
- Topics: dbi, dbplyr, dplyr, r, reusable-functions, rstats, tidyverse
- Language: R
- Homepage:
- Size: 81.1 KB
- Stars: 63
- Watchers: 7
- Forks: 2
- Open Issues: 1
-
Metadata Files:
- Readme: README.Rmd
- License: LICENSE
Awesome Lists containing this project
README
---
output: github_document
---
```{r setup, include = FALSE}
knitr::opts_chunk$set(
collapse = TRUE,
comment = "#>",
fig.path = "man/figures/README-",
out.width = "100%"
)
```
# casewhen
[](https://travis-ci.org/RLesur/casewhen) [](https://codecov.io/github/RLesur/casewhen?branch=master) [](https://www.tidyverse.org/lifecycle/#experimental) [](https://cran.r-project.org/package=casewhen)
The goal of casewhen is to create reusable `dplyr::case_when()` functions.
`SAS` users may recognise a behavior close to the `SAS FORMATS`.
## Installation
You can install the development version from [GitHub](https://github.com/) with:
``` r
# install.packages("devtools")
devtools::install_github("RLesur/casewhen")
```
## Motivation
During data wrangling with `dplyr`, one may use several times identical `case_when()` clauses in different steps. This can lead to a non-DRY code.
This package provides a convenient mean to define and reuse `dplyr::case_when()` functions.
## Examples
With `casewhen`, you can easily create reusable `dplyr::case_when()` functions with the function `create_case_when()`:
```{r example1, message=FALSE}
library(dplyr)
library(casewhen)
people <- tribble(
~name, ~sex, ~seek,
"Mary", "F", "M",
"Henry", "M", "F"
)
cw_sex <- create_case_when(
x == "F" ~ "Woman",
x == "M" ~ "Man",
TRUE ~ as.character(x),
vars = "x"
)
people %>%
mutate(sex_label = cw_sex(sex),
seek_label = cw_sex(seek))
```
Reusing a `case_when()` function is mainly convenient when the same transformation is performed across different datasets.
```{r example2, message=FALSE}
cw_sexyverse <- create_case_when(
x == "F" | x == "female" & y == "Human" ~ "Woman",
x == "M" | x == "male" & y == "Human" ~ "Man",
TRUE ~ as.character(x),
vars = c("x", "y")
)
people %>%
mutate(sex_label = cw_sexyverse(sex, "Human"))
starwars %>%
mutate(sex_label = cw_sexyverse(gender, species)) %>%
select(name, gender, species, sex_label) %>%
head()
```
## `dbplyr` support
You only have to register the `case_when` functions to your connection:
```{r, include=FALSE}
knitr::knit_hooks$set(
message = function(x, options) {
x <- sub("", "", x)
x <- gsub("CASE\n", "\n CASE\n", x, fixed = TRUE)
x <- gsub("\nWHEN", "\n WHEN", x, fixed = TRUE)
x <- gsub("\nEND", "\n END", x, fixed = TRUE)
paste0("**``**\n```sql", paste0(x, collapse = "\n"), "```")
}
)
```
```{r dbplyr, collapse=FALSE, comment=""}
con <-
DBI::dbConnect(RSQLite::SQLite(), ":memory:") %>%
add_case_when(cw_sex, cw_sexyverse)
people_db <- copy_to(con, people)
starwars_db <- copy_to(con, starwars %>% select(name, gender, species))
people_db %>%
mutate(sex_label = cw_sex(sex),
seek_label = cw_sex(seek)) %>%
show_query()
people_db %>%
mutate(sex_label = cw_sexyverse(sex, "Human")) %>%
show_query()
starwars_db %>%
mutate(sex_label = cw_sexyverse(gender, species)) %>%
show_query()
DBI::dbDisconnect(con)
```