multigsub {qdap}

Multiple gsub

Description

multigsub - A wrapper for gsub that takes a vector of search terms and a vector or single value of replacements.

sub_holder - This function holds the place for particular character values, allowing the user to manipulate the vector and then revert the place holders back to the original values.

Usage

multigsub(
  pattern,
  replacement,
  text.var,
  leadspace = FALSE,
  trailspace = FALSE,
  fixed = TRUE,
  trim = TRUE,
  order.pattern = fixed,
  ...
)

mgsub(
  pattern,
  replacement,
  text.var,
  leadspace = FALSE,
  trailspace = FALSE,
  fixed = TRUE,
  trim = TRUE,
  order.pattern = fixed,
  ...
)

sub_holder(pattern, text.var, alpha.type = TRUE, ...)

Arguments

pattern

Character string to be matched in the given character vector.

replacement

Character string equal in length to pattern or of length one which are a replacement for matched pattern.

text.var

The text variable.

leadspace

logical. If TRUE inserts a leading space in the replacements.

trailspace

logical. If TRUE inserts a trailing space in the replacements.

fixed

logical. If TRUE, pattern is a string to be matched as is. Overrides all conflicting arguments.

trim

logical. If TRUE leading and trailing white spaces are removed and multiple white spaces are reduced to a single white space.

order.pattern

logical. If TRUE and fixed = TRUE, the pattern string is sorted by number of characters to prevent substrings replacing meta strings (e.g., pattern = c("the", "then") resorts to search for "then" first).

...

Additional arguments passed to gsub.

alpha.type

logical. If TRUE alpha (lower case letters) are used for the key. If FALSE numbers are used as the key.

Value

multigsub - Returns a vector with the pattern replaced.

sub_holder - Returns a list with the following:

output

keyed place holder character vector

unhold

A function used to revert back to the original values

Note

The unhold function for sub_holder will only work on keys that have not been disturbed by subsequent alterations. The key follows the pattern of 'qdapplaceholder' followed by lower case letter keys followed by 'qdap'.

See Also

gsub

Examples

## Not run: 
## ======================
##    `mgsub` Function
## ======================

multigsub(c("it's", "I'm"), c("it is", "I am"), DATA$state)
mgsub(c("it's", "I'm"), c("it is", "I am"), DATA$state)
mgsub("[[:punct:]]", "PUNC", DATA$state, fixed = FALSE)

## ====================== 
## `sub_holder` Function
## ======================

## `alpha.type` as TRUE
(fake_dat <- paste(emoticon[1:11,2], DATA$state))
(m <- sub_holder(emoticon[,2], fake_dat))
m$unhold(strip(m$output))
# With Stemming
m$unhold(stemmer(strip(m$output), capitalize = FALSE))

## `alpha.type` as FALSE (numeric keys)
vowels <- LETTERS[c(1, 5, 9, 15, 21)]
(m2 <- sub_holder(vowels, toupper(DATA$state), alpha.type = FALSE))
m2$unhold(gsub("[^0-9]", "", m2$output))
mtabulate(strsplit(m2$unhold(gsub("[^0-9]", "", m2$output)), ""))

## End(Not run)