tosca (version 0.3-4)

LDAprep: Create Lda-ready Dataset

Description

This function transforms a text corpus such as the result of cleanTexts into the form needed by the lda-package.

Usage

LDAprep(text, vocab, reduce = TRUE)

Value

A list in which every entry contains a matrix with two rows: The first row gives the number of the entry of the word in vocab minus one, the second row is 1 and the number of the occurrence of the word will be shown by the number of columns belonging to this word.

Arguments

text

A list of tokenized texts

vocab

A character vector containing all words which should beused for lda

reduce

Logical: Should empty texts be deleted?

Examples

texts <- list(A="Give a Man a Fish, and You Feed Him for a Day.
Teach a Man To Fish, and You Feed Him for a Lifetime",
B="So Long, and Thanks for All the Fish",
C="A very able manipulative mathematician, Fisher enjoys a real mastery
in evaluating complicated multiple integrals.")

corpus <- textmeta(meta=data.frame(id=c("A", "B", "C", "D"),
title=c("Fishing", "Don't panic!", "Sir Ronald", "Berlin"),
date=c("1885-01-02", "1979-03-04", "1951-05-06", "1967-06-02"),
additionalVariable=1:4, stringsAsFactors=FALSE), text=texts)

corpus <- cleanTexts(corpus)
wordlist <- makeWordlist(corpus$text)
LDAprep(text=corpus$text, vocab=wordlist$words, reduce = TRUE)