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```{r, include=FALSE}
# So the second library() call doesn't show messages
library(tidyverse)
```
Here we show the usage for the basic selection operators. See the
specific help pages to learn about helpers like [starts_with()].
The selection language can be used in functions like
`dplyr::select()` or `tidyr::pivot_longer()`. Let's first attach
the tidyverse:
```{r}
library(tidyverse)
# For better printing
iris <- as_tibble(iris)
```
Select variables by name:
```{r}
starwars %>% select(height)
iris %>% pivot_longer(Sepal.Length)
```
Select multiple variables by separating them with commas. Note how
the order of columns is determined by the order of inputs:
```{r}
starwars %>% select(homeworld, height, mass)
```
Functions like `tidyr::pivot_longer()` don't take variables with
dots. In this case use `c()` to select multiple variables:
```{r}
iris %>% pivot_longer(c(Sepal.Length, Petal.Length))
```
## Operators:
The `:` operator selects a range of consecutive variables:
```{r}
starwars %>% select(name:mass)
```
The `!` operator negates a selection:
```{r}
starwars %>% select(!(name:mass))
iris %>% select(!c(Sepal.Length, Petal.Length))
iris %>% select(!ends_with("Width"))
```
`&` and `|` take the intersection or the union of two selections:
```{r}
iris %>% select(starts_with("Petal") & ends_with("Width"))
iris %>% select(starts_with("Petal") | ends_with("Width"))
```
To take the difference between two selections, combine the `&` and
`!` operators:
```{r}
iris %>% select(starts_with("Petal") & !ends_with("Width"))
```
|
