stm (version 1.1.3)

convertCorpus: Convert stm formatted documents to another format

Description

Takes an stm formatted documents and vocab object and returns formats useable in other packages.

Usage

convertCorpus(documents, vocab, type=c("slam", "lda", "Matrix"))

Arguments

documents

the documents object in stm format

vocab

the vocab object in stm format

type

the output type desired. See Details.

Details

The various type conversions are described below:

type="slam"

Converts to the simple triplet matrix representation used by the slam package. This is the format used internally by tm.

type="lda"

Converts to the format used by the lda package. This is a very minor change as the format in stm is based on lda's data representation. The difference as noted in stm involves how the numbers are indexed. Accordingly this type returns a list containing the new documents object and the unchanged vocab object.

type="Matrix"

Converts to the sparse matrix representation used by Matrix. This is the format used internally by numerous other text analysis packages.

If you want to write out a file containing the sparse matrix representation popularized by David Blei's C code ldac see the function writeLdac.

See Also

writeLdac readCorpus poliblog5k

Examples

#convert the poliblog5k data to slam package format
poliSlam <- convertCorpus(poliblog5k.docs, poliblog5k.voc, type="slam")
class(poliSlam)