The tm package extends c so that, if given a set of PlainTextDocuments it automatically creates a Corpus. Unfortunately, it appears that each PlainTextDocument must be specified separately.
e.g. if I had:
foolist <- list(a, b, c); # where a,b,c are PlainTextDocument objects
I'd do this to get a Corpus:
foocorpus <- c(foolist[[1]], foolist[[2]], foolist[[3]]);
I have a list of lists of 'PlainTextDocuments that looks like this:
> str(sectioned)
List of 154
$ :List of 6
..$ :Classes 'PlainTextDocument', 'TextDocument', 'character' atomic [1:1] Developing assessment models Developing models
.. .. ..- attr(*, "Author")= chr "John Smith"
.. .. ..- attr(*, "DateTimeStamp")= POSIXlt[1:1], format: "2013-04-30 12:03:49"
.. .. ..- attr(*, "Description")= chr(0)
.. .. ..- attr(*, "Heading")= chr "Research Focus"
.. .. ..- attr(*, "ID")= chr(0)
.. .. ..- attr(*, "Language")= chr(0)
.. .. ..- attr(*, "LocalMetaData")=List of 4
.. .. .. ..$ foo : chr "bar"
.. .. .. ..$ classification: chr "Technician"
.. .. .. ..$ team : chr ""
.. .. .. ..$ supervisor : chr "Bill Jones"
.. .. ..- attr(*, "Origin")= chr "Smith-John_e.txt"
#etc., all sublists have 6 elements
So, to get all my PlainTextDocuments into a Corpus, this would work:
sectioned.Corpus <- c(sectioned[[1]][[1]], sectioned[[1]][[2]], ..., sectioned[[154]][[6]])
Can anyone suggest an easier way, please?
ETA: foo<-unlist(foolist, recursive=FALSE) produces a flat list of PlainTextDocuments, which still leaves me with the problem of feeding a list element by element to c
Answer
I expect that unlist(foolist) will help you. It has an option recursive which is TRUE by default.
So unlist(foolist, recursive = FALSE) will return the list of the documents, and then you can combine them by:
do.call(c, unlist(foolist, recursive=FALSE))
do.call just applies the function c to the elements of the obtained list