ifiles: Creates iterator over text files from the disk

In text2vec: Modern Text Mining Framework for R

Description

The result of this function usually used in an itoken function.

Usage

ifiles(file_paths, reader = readLines)

idir(path, reader = readLines)

ifiles_parallel(file_paths, reader = readLines,
  n_chunks = foreach::getDoParWorkers())

Arguments

file_paths	character paths of input files
reader	function which will perform reading of text files from disk, which should take a path as its first argument. reader() function should return named character vector: elements of vector = documents, names of the elements = document ids which will be used in DTM construction. If user doesn't provide named character vector, document ids will be generated as file_name + line_number (assuming that each line is a document).
path	character path of directory. All files in the directory will be read.
n_chunks	integer, defines in how many chunks files will be processed. For example if you have 32 files, and n_chunks = 8, then for each 4 files will be created a job (for example document-term matrix construction). In case some parallel backend registered, each job will be evaluated in a separated thread (process) in parallel. So each such group of files will be processed in parallel and at the end all 8 results from will be combined.

See Also

itoken

Examples

## Not run: 
current_dir_files = list.files(path = ".", full.names = TRUE)
files_iterator = ifiles(current_dir_files)
parallel_files_iterator = ifiles_parallel(current_dir_files, n_chunks = 4)
it = itoken_parallel(parallel_files_iterator)
dtm = create_dtm(it, hash_vectorizer(2**16), type = 'dgTMatrix')

## End(Not run)
dir_files_iterator = idir(path = ".")

text2vec documentation built on Jan. 12, 2018, 1:04 a.m.