tm (version 0.5-10)

TermDocumentMatrix: Term-Document Matrix

Description

Constructs or coerces to a term-document matrix or a document-term matrix.

Usage

TermDocumentMatrix(x, control = list())
DocumentTermMatrix(x, control = list())
as.TermDocumentMatrix(x, ...)
as.DocumentTermMatrix(x, ...)

Arguments

x

a corpus for the constructors and either a term-document matrix or a document-term matrix or a simple triplet matrix (package slam) or a

control

a named list of control options. There are local options which are evaluated for each document and global options which are evaluated once for the constructed matrix. Available local options are documented in

...

the additional argument weighting (typically a WeightFunction) is allowed when coercing a simple triplet matrix to a term-document or document-term matrix.

Value

• An object of class TermDocumentMatrix or class DocumentTermMatrix (both inheriting from a simple triplet matrix in package slam) containing a sparse term-document matrix or document-term matrix. The attribute Weighting contains the weighting applied to the matrix.

See Also

termFreq for available local control options.

Examples

data("crude")
tdm <- TermDocumentMatrix(crude,
                          control = list(removePunctuation = TRUE,
                                         stopwords = TRUE))
dtm <- DocumentTermMatrix(crude,
                          control = list(weighting =
                                         function(x)
                                         weightTfIdf(x, normalize =
                                                     FALSE),
                                         stopwords = TRUE))
inspect(tdm[155:160,1:5])
inspect(tdm[c("price", "texas"),c("127","144","191","194")])
inspect(dtm[1:5,155:160])