quanteda (version 1.3.13)

dfm_replace: Replace features in dfm

Description

Substitute features based on vectorized one-to-one matching for lemmatization or user-defined stemming.

Usage

dfm_replace(x, pattern, replacement = NULL, case_insensitive = TRUE,
  verbose = quanteda_options("verbose"))

Arguments

x

dfm whose features will be replaced

pattern

a character vector or dictionary. See pattern for more details.

replacement

if pattern is a character vector, then replacement must be character vector of equal length, for a 1:1 match. If pattern is a dictionary, then replacement should not be used.

case_insensitive

ignore case when matching, if TRUE

verbose

print status messages if TRUE

Examples

# NOT RUN {
mydfm <- dfm(data_corpus_irishbudget2010)

# lemmatization
infle <- c("foci", "focus", "focused", "focuses", "focusing", "focussed", "focusses")
lemma <- rep("focus", length(infle))
mydfm2 <- dfm_replace(mydfm, infle, lemma)
featnames(dfm_select(mydfm2, infle))

# stemming
feat <- featnames(mydfm)
stem <- char_wordstem(feat, "porter")
mydfm3 <- dfm_replace(mydfm, feat, stem, case_insensitive = FALSE)
identical(mydfm3, dfm_wordstem(mydfm, "porter"))
# }