R: Extract non-numbers from a string.

str_extract_non_numerics {strex} | R Documentation

## Extract non-numbers from a string.

### Description

`str_extract_non_numerics` extracts the bits of the string that aren't extracted by `extract_numbers`. `str_nth_non_numeric` is a convenient wrapper for `str_extract_non_numerics`, allowing you to choose which number you want. Please run the examples at the bottom of this page to ensure that you understand how these functions work, and their limitations. These functions are vectorized over `string`.

### Usage

    str_extract_non_numerics(string, decimals = FALSE,
      leading_decimals = FALSE, negs = FALSE)

    str_nth_non_numeric(string, n, decimals = FALSE,
      leading_decimals = FALSE, negs = FALSE)

    str_first_non_numeric(string, decimals = FALSE,
      leading_decimals = FALSE, negs = FALSE)

    str_last_non_numeric(string, decimals = FALSE,
      leading_decimals = FALSE, negs = FALSE)

### Arguments

`string` | A string.
`decimals` | Do you want to include the possibility of decimal numbers (`TRUE`) or not (`FALSE`, the default).
`leading_decimals` | Do you want to allow a leading decimal point to be the start of a number?
`negs` | Do you want to allow negative numbers? Note that double negatives are not handled here (see the examples).
`n` | The index of the number (or non-numeric) that you seek. Negative indexing is allowed i.e. `n = 1` (the default) will give you the first number (or non-numeric) whereas `n = -1` will give you the last number (or non-numeric), `n = -2` will give you the second last number and so on. The function is vectorized over this argument.

### Details

- `str_first_non_numeric(...)` is just `str_nth_non_numeric(..., n = 1)`.

- `str_last_non_numeric(...)` is just `str_nth_non_numeric(..., n = -1)`.

### Examples

    str_extract_non_numerics("abc123abc456")
    str_extract_non_numerics("abc1.23abc456")
    str_extract_non_numerics("abc1.23abc456", decimals = TRUE)
    str_extract_non_numerics("abc1..23abc456", decimals = TRUE)
    str_extract_non_numerics("abc1..23abc456", decimals = TRUE,
                         leading_decimals = TRUE)
    str_extract_non_numerics(c("-123abc456", "ab1c"))
    str_extract_non_numerics("-123abc456", negs = TRUE)
    str_extract_non_numerics("--123abc456", negs = TRUE)
    str_extract_non_numerics("--123abc456", negs = TRUE)
    str_nth_non_numeric("--123abc456", 1)
    str_nth_non_numeric("--123abc456", -2)

[Package strex version 0.1.3 Index]