create_matrix.R

#-------------------------------------------------------------------------------------------------------------

#Creating a Document Term Matrix to analyze data

create_matrix <- function(textColumns, language="english", minDocFreq=1, minWordLength=3, removeNumbers=TRUE, removePunctuation=TRUE, removeSparseTerms=0, removeStopwords=TRUE, stemWords=FALSE, stripWhitespace=TRUE, toLower=TRUE){ 
  
  stem_words <- function(x) {
    split <- strsplit(x," ")
    return(wordStem(split[[1]],language=language))
  }
  
  control <- list(language=language,tolower=toLower,removeNumbers=removeNumbers,removePunctuation=removePunctuation,stripWhitespace=stripWhitespace,minWordLength=minWordLength,stopwords=removeStopwords,minDocFreq=minDocFreq) 
  
  if (stemWords == TRUE) control <- append(control,list(stemming=stem_words),after=6)
  
  trainingColumn <- apply(as.matrix(textColumns),1,paste,collapse=" ")
  trainingColumn <- sapply(as.vector(trainingColumn,mode="character"),iconv,to="UTF8",sub="byte")
  
  corpus <- Corpus(VectorSource(trainingColumn),readerControl=list(language=language))
  matrix <- DocumentTermMatrix(corpus,control=control);
  if (removeSparseTerms > 0) matrix <- removeSparseTerms(matrix,removeSparseTerms)
  
  gc()
  return(matrix)
}

#-------------------------------------------------------------------------------------------------------------# R-Complaint-Classifier