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Tidyselect columns in stata style

Source: R/s_match.R
s_match.Rd

s_match() is a simpler version of matches() in <tidy-select>. It is designed to select columns in a Stata-like style.

As matches(), s_match() must be used within a selecting function, such as ds() or dplyr::across().

Usage

s_match(string, ignore.case = TRUE, vars = NULL)

Arguments

string

A character vector of column names like selecting a varlist in Stata keep command.

ignore.case

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

vars

A character vector of variable names. If not supplied, the variables are taken from the current selection context (as established by functions like select() or pivot_longer()).

Details

  • * matches zero or more characters.

  • ~ matches one or more characters.

  • ? matches one character.

  • [a-h] matches any character in the range from a to h.

  • [1-12] matches any number in the range from 1 to 12.

  • var1-var5 is NOT used to select a range of variables. Use var1:var5 out of s_match() instead.

Examples

tb <- paste0("x", 1:15) %>%
  tibble::as_tibble() %>%
  tidyr::pivot_wider(names_from = value)
tb
#> # A tibble: 1 × 15
#>   x1    x2    x3    x4    x5    x6    x7    x8    x9    x10   x11   x12   x13  
#>   <chr> <chr> <chr> <chr> <chr> <chr> <chr> <chr> <chr> <chr> <chr> <chr> <chr>
#> 1 x1    x2    x3    x4    x5    x6    x7    x8    x9    x10   x11   x12   x13  
#> # ℹ 2 more variables: x14 <chr>, x15 <chr>

# List variable names by ds()
ds(tb)
#>  [1] "x1"  "x2"  "x3"  "x4"  "x5"  "x6"  "x7"  "x8"  "x9"  "x10" "x11" "x12"
#> [13] "x13" "x14" "x15"

tb %>%
  ds(s_match("x1*"))
#> [1] "x1"  "x10" "x11" "x12" "x13" "x14" "x15"

tb %>%
  ds(s_match("x1~"))
#> [1] "x10" "x11" "x12" "x13" "x14" "x15"

tb %>%
  ds(s_match("*5"))
#> [1] "x5"  "x15"

tb %>%
  ds(s_match("?5"))
#> [1] "x5"

tb %>%
  ds(s_match("x[9-15]"))
#> [1] "x9"  "x10" "x11" "x12" "x13" "x14" "x15"

if (FALSE) {
tb %>%
  ds(s_match("x1-x5"))
}

tb %>%
  ds(x1:x5)
#> [1] "x1" "x2" "x3" "x4" "x5"