R: Group near elements of string vectors

group_str {sjmisc}

R Documentation

Group near elements of string vectors

Description

This function groups elements of a string vector (character or string variable) according to the element's distance ('similatiry'). The more similar two string elements are, the higher is the chance to be combined into a group.

Usage

group_str(strings, maxdist = 2, method = "lv", strict = FALSE,
  trim.whitespace = TRUE, remove.empty = TRUE, showProgressBar = FALSE)

Arguments

`strings`	Character vector with string elements.
`maxdist`	Maximum distance between two string elements, which is allowed to treat two elements as similar or equal.
`method`	Method for distance calculation. The default is `"lv"`. See `stringdist` for details.
`strict`	Logical; if `TRUE`, value matching is more strictly. See 'Examples'.
`trim.whitespace`	Logical; if `TRUE` (default), leading and trailing white spaces will be removed from string values.
`remove.empty`	Logical; if `TRUE` (default), empty string values will be removed from the character vector `strings`.
`showProgressBar`	Logical; if `TRUE`, the progress bar is displayed when computing the distance matrix. Default in `FALSE`, hence the bar is hidden.

Value

A character vector where similar string elements (values) are recoded into a new, single value. The return value is of same length as strings, i.e. grouped elements appear multiple times, so the count for each grouped string is still avaiable (see 'Examples').

Examples

oldstring <- c("Hello", "Helo", "Hole", "Apple",
               "Ape", "New", "Old", "System", "Systemic")
newstring <- group_str(oldstring)

# see result
newstring

# count for each groups
table(newstring)

# print table to compare original and grouped string
frq(oldstring)
frq(newstring)

# larger groups
newstring <- group_str(oldstring, maxdist = 3)
frq(oldstring)
frq(newstring)

# be more strict with matching pairs
newstring <- group_str(oldstring, maxdist = 3, strict = TRUE)
frq(oldstring)
frq(newstring)