udpipe (version 0.8.11)

dtm_conform: Make sure a document term matrix has exactly the specified rows and columns

Description

Makes sure the document term matrix has exactly the rows and columns which you specify. If missing rows or columns are occurring, the function fills these up either with empty cells or with the value that you provide. See the examples.

Usage

dtm_conform(dtm, rows, columns, fill)

Value

the sparse matrix dtm with exactly the specified rows and columns

Arguments

dtm

a document term matrix: an object returned by document_term_matrix

rows

a character vector of row names which dtm should have

columns

a character vector of column names which dtm should have

fill

a value to use to fill up missing rows / columns. Defaults to using an empty cell.

See Also

document_term_matrix

Examples

x <- data.frame(doc_id = c("doc_1", "doc_1", "doc_1", "doc_2"), 
                text = c("a", "a", "b", "c"), 
                stringsAsFactors = FALSE)
dtm <- document_term_frequencies(x)
dtm <- document_term_matrix(dtm)
dtm
dtm_conform(dtm, 
            rows = c("doc_1", "doc_2", "doc_3"), columns = c("a", "b", "c", "Z", "Y"))
dtm_conform(dtm, 
            rows = c("doc_1", "doc_2", "doc_3"), columns = c("a", "b", "c", "Z", "Y"), 
            fill = 1)
dtm_conform(dtm, rows = c("doc_1", "doc_3"), columns = c("a", "b", "c", "Z", "Y"))
dtm_conform(dtm, columns = c("a", "b", "Z"))
dtm_conform(dtm, rows = c("doc_1"))
dtm_conform(dtm, rows = character())
dtm_conform(dtm, columns = character())
dtm_conform(dtm, rows = character(), columns = character())

##
## Some examples on border line cases
##
special1 <- dtm[, character()]
special2 <- dtm[character(), character()]
special3 <- dtm[character(), ]

dtm_conform(special1, 
            rows = c("doc_1", "doc_2", "doc_3"), columns = c("a", "b", "c", "Z", "Y"))
dtm_conform(special1, 
            rows = c("doc_1", "doc_2", "doc_3"), columns = c("a", "b", "c", "Z", "Y"), 
            fill = 1)
dtm_conform(special1, rows = c("doc_1", "doc_3"), columns = c("a", "b", "c", "Z", "Y"))
dtm_conform(special1, columns = c("a", "b", "Z"))
dtm_conform(special1, rows = c("doc_1"))
dtm_conform(special1, rows = character())
dtm_conform(special1, columns = character())
dtm_conform(special1, rows = character(), columns = character())

dtm_conform(special2, 
            rows = c("doc_1", "doc_2", "doc_3"), columns = c("a", "b", "c", "Z", "Y"))
dtm_conform(special2, 
            rows = c("doc_1", "doc_2", "doc_3"), columns = c("a", "b", "c", "Z", "Y"), 
            fill = 1)
dtm_conform(special2, rows = c("doc_1", "doc_3"), columns = c("a", "b", "c", "Z", "Y"))
dtm_conform(special2, columns = c("a", "b", "Z"))
dtm_conform(special2, rows = c("doc_1"))
dtm_conform(special2, rows = character())
dtm_conform(special2, columns = character())
dtm_conform(special2, rows = character(), columns = character())

dtm_conform(special3, 
            rows = c("doc_1", "doc_2", "doc_3"), columns = c("a", "b", "c", "Z", "Y"))
dtm_conform(special3, 
            rows = c("doc_1", "doc_2", "doc_3"), columns = c("a", "b", "c", "Z", "Y"), 
            fill = 1)
dtm_conform(special3, rows = c("doc_1", "doc_3"), columns = c("a", "b", "c", "Z", "Y"))
dtm_conform(special3, columns = c("a", "b", "Z"))
dtm_conform(special3, rows = c("doc_1"))
dtm_conform(special3, rows = character())
dtm_conform(special3, columns = character())
dtm_conform(special3, rows = character(), columns = character())