select_helpers: Select helpers

Description Usage Arguments Value Examples

Description

These functions allow you to select variables based on their names.

Usage

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
starts_with(match, ignore.case = TRUE, vars = peek_vars())

ends_with(match, ignore.case = TRUE, vars = peek_vars())

contains(match, ignore.case = TRUE, vars = peek_vars())

matches(match, ignore.case = TRUE, vars = peek_vars())

num_range(prefix, range, width = NULL, vars = peek_vars())

one_of(..., .vars = peek_vars())

everything(vars = peek_vars())

last_col(offset = 0L, vars = peek_vars())

Arguments

match

A string.

ignore.case

If TRUE, the default, ignores case when matching names.

vars, .vars

A character vector of variable names. When called from inside selecting functions like dplyr::select() these are automatically set to the names of the table.

prefix

A prefix that starts the numeric range.

range

A sequence of integers, like 1:5.

width

Optionally, the "width" of the numeric range. For example, a range of 2 gives "01", a range of three "001", etc.

...

One or more character vectors.

offset

Set it to n to select the nth var from the end.

Value

An integer vector giving the position of the matched variables.

Examples

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
nms <- names(iris)
vars_select(nms, starts_with("Petal"))
vars_select(nms, ends_with("Width"))
vars_select(nms, contains("etal"))
vars_select(nms, matches(".t."))
vars_select(nms, Petal.Length, Petal.Width)
vars_select(nms, everything())
vars_select(nms, last_col())
vars_select(nms, last_col(offset = 2))

vars <- c("Petal.Length", "Petal.Width")
vars_select(nms, one_of(vars))

Example output

  Petal.Length    Petal.Width 
"Petal.Length"  "Petal.Width" 
  Sepal.Width   Petal.Width 
"Sepal.Width" "Petal.Width" 
  Petal.Length    Petal.Width 
"Petal.Length"  "Petal.Width" 
  Sepal.Length    Sepal.Width   Petal.Length    Petal.Width 
"Sepal.Length"  "Sepal.Width" "Petal.Length"  "Petal.Width" 
  Petal.Length    Petal.Width 
"Petal.Length"  "Petal.Width" 
  Sepal.Length    Sepal.Width   Petal.Length    Petal.Width        Species 
"Sepal.Length"  "Sepal.Width" "Petal.Length"  "Petal.Width"      "Species" 
  Species 
"Species" 
  Petal.Length 
"Petal.Length" 
  Petal.Length    Petal.Width 
"Petal.Length"  "Petal.Width" 

tidyselect documentation built on May 2, 2019, 9:43 a.m.