textclean (version 0.9.3)

replace_tokens: Replace Tokens

Description

Replace tokens with a single substring. This is much faster than mgsub if one wants to replace fixed tokens with a single value or remove them all together. This can be useful for quickly replacing tokens like names in string with a single value in order to reduce noise.

Usage

replace_tokens(x, tokens, replacement = NULL, ignore.case = FALSE, ...)

Arguments

x

A character vector.

tokens

A vector of token to be replaced.

replacement

A single character string to replace the tokens with. The default, NULL, replaces the tokens with nothing.

ignore.case

logical. If TRUE the case of the tokens will be ignored.

…

ignored.

Value

Returns a vector of strings with tokens replaced.

See Also

mgsub, match_tokens

Examples

# NOT RUN {
replace_tokens(DATA$state, c('No', 'what', "it's"))
replace_tokens(DATA$state, c('No', 'what', "it's"), "<<TOKEN>>")
replace_tokens(
    DATA$state, 
    c('No', 'what', "it's"), 
    "<<TOKEN>>", 
    ignore.case = TRUE
)

# }
# NOT RUN {
## Now let's see the speed
## Set up data
library(textshape)
data(hamlet)
set.seed(11)
tokens <- sample(unique(unlist(split_token(hamlet$dialogue))), 2000)

tic <- Sys.time()
head(replace_tokens(hamlet$dialogue, tokens))
(toc <- Sys.time() - tic)


tic <- Sys.time()
head(mgsub(hamlet$dialogue, tokens, ""))
(toc <- Sys.time() - tic)


## Amp it up 20x more data
tic <- Sys.time()
head(replace_tokens(rep(hamlet$dialogue, 20), tokens))
(toc <- Sys.time() - tic)

## Replace names example

library(lexicon)
library(textshape)
nms <- gsub("(^.)(.*)", "\\U\\1\\L\\2", common_names, perl = TRUE)
x <- split_portion(
    sample(c(sample(grady_augmented, 5000), sample(nms, 10000, TRUE))), 
    n.words = 12
)
x$text.var <- paste0(
    x$text.var, 
    sample(c('.', '!', '?'), length(x$text.var), TRUE)
 )
replace_tokens(x$text.var, nms, 'NAME')
# }