Question

I am using RTextTools to build a training set with a matrix and a model which I will later apply to different documents to classify them.

EDIT: The matrix is a Document Term Matrix

The problem I am having is that sometimes with certain documents when I create the new_matrix with the following line

new_matrix <- create_matrix(data$document,language="english", removeNumbers=FALSE, removePunctuation=TRUE, removeStopwords=TRUE, toLower=TRUE, stemWords=TRUE, minDocFreq=1,weighting=weightTfIdf,originalMatrix=matrix)

I get some NaN values which make my corpus fail

corpus <- create_corpus(new_matrix,data$value, testSize=1:100,virgin=FALSE)

With the error

Error in .csr.coo(x) : NA/NaN/Inf in foreign function call (arg 4)

I am not sure why there are some NaN values. My guess is that it has to do with some words being present on the new_matrix and not on the original matrix.

How can I change NaN values for a 0 in the resulting matrix?

Will doing that alter the result of the classification?

Any help much appreciated! Thanks!

Answer 1

Simple way to find NaN values by using is.na():

data<-c(1,2,NaN,4,2)
data[is.na(data)]<-0
data

[1] 1 2 0 4 2