pdfsearch (version 0.4.1)

keyword_directory: Wrapper for keyword search function

Description

This will use the keyword_search function to loop over all pdf files in a directory. Includes the ability to include subdirectories as well.

Usage

keyword_directory(
  directory,
  keyword,
  surround_lines = FALSE,
  ignore_case = FALSE,
  token_results = TRUE,
  split_pdf = FALSE,
  remove_hyphen = TRUE,
  convert_sentence = TRUE,
  remove_equations = TRUE,
  split_pattern = "\\p{WHITE_SPACE}{3,}",
  full_names = TRUE,
  file_pattern = ".pdf",
  recursive = FALSE,
  max_search = NULL,
  ...
)

Value

A tibble data frame that contains the keyword, location of match, the line of text match, and optionally the tokens associated with the line of text match. The output is combined (row binded) for all pdf input files.

Arguments

directory

The directory to perform the search for pdf files to search.

keyword

The keyword(s) to be used to search in the text. Multiple keywords can be specified with a character vector.

surround_lines

numeric/FALSE indicating whether the output should extract the surrouding lines of text in addition to the matching line. Default is FALSE, if not false, include a numeric number that indicates the additional number of surrounding lines that will be extracted.

ignore_case

TRUE/FALSE/vector of TRUE/FALSE, indicating whether the case of the keyword matters. Default is FALSE meaning that case of the keyword is literal. If a vector, must be same length as the keyword vector.

token_results

TRUE/FALSE indicating whether the results text returned should be split into tokens. See the tokenizers package and convert_tokens for more details. Defaults to TRUE.

split_pdf

TRUE/FALSE indicating whether to split the pdf using white space. This would be most useful with multicolumn pdf files. The split_pdf function attempts to recreate the column layout of the text into a single column starting with the left column and proceeding to the right.

remove_hyphen

TRUE/FALSE indicating whether hyphenated words should be adjusted to combine onto a single line. Default is TRUE.

convert_sentence

TRUE/FALSE indicating if individual lines of PDF file should be collapsed into a single large paragraph to perform keyword searching. Default is TRUE.

remove_equations

TRUE/FALSE indicating if equations should be removed. Default behavior is to search for a literal parenthesis, followed by at least one number followed by another parenthesis at the end of the text line. This will not detect other patterns or detect the entire equation if it is a multi-row equation.

split_pattern

Regular expression pattern used to split multicolumn PDF files using stringi::stri_split_regex. Default pattern is to split based on three or more consecutive white space characters.

full_names

TRUE/FALSE indicating if the full file path should be used. Default is TRUE, see list.files for more details.

file_pattern

An optional regular expression to select specific file names. Only files that match the regular expression will be searched. Defaults to all pdfs, i.e. ".pdf". See list.files for more details.

recursive

TRUE/FALSE indicating if subdirectories should be searched as well. Default is FALSE, see list.files for more details.

max_search

An optional numeric vector indicating the maximum number of pdfs to search. Will only search the first n cases.

...

token_function to pass to convert_tokens function.

Examples

# find directory
directory <- system.file('pdf', package = 'pdfsearch')

# do search over two files
keyword_directory(directory, 
       keyword = c('repeated measures', 'measurement error'),
       surround_lines = 1, full_names = TRUE)
       
# can also split pdfs
keyword_directory(directory, 
       keyword = c('repeated measures', 'measurement error'),
       split_pdf = TRUE, remove_hyphen = FALSE,
       surround_lines = 1, full_names = TRUE)