Word_Frequency_Matrix: Word Frequency Matrix

In trinker/qdap2: Bridging the gap between qualitative data and quantitative analysis

Description

wfm - Generate a word frequency matrix by grouping variable(s).

wfdf - Generate a word frequency data frame by grouping variable.

wfm.expanded - Expand a word frequency matrix to have multiple rows for each word.

wf.combine - Combines words (rows) of a word frequency data frame (wfdf) together.

Usage

  wfm(text.var = NULL, grouping.var = NULL, wfdf = NULL,
    output = "raw", stopwords = NULL, digits = 2,
    char2space = "~~", ...)

  wfdf(text.var, grouping.var = NULL, stopwords = NULL,
    margins = FALSE, output = "raw", digits = 2,
    char2space = "~~", ...)

  wfm.expanded(text.var, grouping.var = NULL, ...)

  wf.combine(wf.obj, word.lists, matrix = FALSE)

Arguments

text.var	The text variable
grouping.var	The grouping variables. Default NULL generates one word list for all text. Also takes a single grouping variable or a list of 1 or more grouping variables.
wfdf	A word frequency data frame given instead of raw text.var and optional grouping.var. Basically converts a word frequency dataframe (wfdf) to a word frequency matrix (wfm). Default is NULL.
output	Output type (either "proportion" or "percent").
stopwords	A vector of stop words to remove.
digits	An integer indicating the number of decimal places (round) or significant digits (signif) to be used. Negative values are allowed
margins	logical. If TRUE provides grouping.var and word variable totals.
...	Other arguments supplied to strip.
wf.obj	A wfm or wfdf object.
word.lists	A list of character vectors of words to pass to wf.combine
matrix	logical. If TRUE returns the output as a wfm rather than a wfdf object.
char2space	A vector of characters to be turned into spaces. If char.keep is NULL, char2space will activate this argument.

Value

wfm - returns a word frequency of the class matrix.

wfdf - returns a word frequency of the class data.frame with a words column and optional margin sums.

wfm.expanded - returns a matrix similar to a word frequency matrix (wfm) but the rows are expanded to represent the maximum usages of the word and cells are dummy coded to indicate that number of uses.

wf.combine - returns a word frequency matrix (wfm) or dataframe (wfdf) with counts for the combined word.lists merged and remaining terms(else).

Note

Words can be kept as one by inserting a double tilde ("~~"), or other character strings passed to char2space, as a single word/entry. This is useful for keeping proper names as a single unit.

Examples

#word frequency matrix (wfm) example:
with(DATA, wfm(state, list(sex, adult)))[1:15, ]
with(DATA, wfm(state, person))[1:15, ]

#insert double tilde ("~~") to keep phrases(i.e. first last name)
alts <- c(" fun", "I ")
state2 <- mgsub(alts, gsub("\\s", "~~", alts), DATA$state)
with(DATA, wfm(state2, list(sex, adult)))[1:18, ]

#word frequency dataframe (wfdf) example:
with(DATA, wfdf(state, list(sex, adult)))[1:15, ]
with(DATA, wfdf(state, person))[1:15, ]

#inset double tilde ("~~") to keep dual words (e.i. first last name)
alts <- c(" fun", "I ")
state2 <- mgsub(alts, gsub("\\s", "~~", alts), DATA$state)
with(DATA, wfdf(state2, list(sex, adult)))[1:18, ]

#wfm.expanded example:
z <- wfm(DATA$state, DATA$person)
wfm.expanded(z)[30:45, ] #two "you"s

#wf.combine examples:
#===================
#raw no margins (will work)
x <- wfm(DATA$state, DATA$person)

#raw with margin (will work)
y <- wfdf(DATA$state, DATA$person, margins = TRUE)

WL1 <- c(y[, 1])
WL2 <- list(c("read", "the", "a"), c("you", "your", "you're"))
WL3 <- list(bob = c("read", "the", "a"), yous = c("you", "your", "you're"))
WL4 <- list(bob = c("read", "the", "a"), yous = c("a", "you", "your", "your're"))
WL5 <- list(yous = c("you", "your", "your're"))
WL6 <- list(c("you", "your", "your're"))  #no name so will be called words 1
WL7 <- c("you", "your", "your're")

wf.combine(z, WL2) #Won't work not a raw frequency matrix
wf.combine(x, WL2) #Works (raw and no margins)
wf.combine(y, WL2) #Works (raw with margins)
wf.combine(y, c("you", "your", "your're"))
wf.combine(y, WL1)
wf.combine(y, WL3)
## wf.combine(y, WL4) #Error
wf.combine(y, WL5)
wf.combine(y, WL6)
wf.combine(y, WL7)

worlis <- c("you", "it", "it's", "no", "not", "we")
y <- wfdf(DATA$state, list(DATA$sex, DATA$adult), margins = TRUE)
z <- wf.combine(y, worlis, matrix = TRUE)

chisq.test(z)
chisq.test(wfm(wfdf = y))

trinker/qdap2 documentation built on May 31, 2019, 9:47 p.m.