Package 'pdfsearch'

Title: Search Tools for PDF Files
Description: Includes functions for keyword search of pdf files. There is also a wrapper that includes searching of all files within a single directory.
Authors: Brandon LeBeau [aut, cre]
Maintainer: Brandon LeBeau <[email protected]>
License: MIT + file LICENSE
Version: 0.3.4
Built: 2025-03-10 04:04:26 UTC
Source: https://github.com/lebebr01/pdfsearch

Help Index

Ability to tokenize words.

Description

Ability to tokenize words.

Usage

convert_tokens(
  x,
  path = FALSE,
  split_pdf = FALSE,
  remove_hyphen = TRUE,
  token_function = NULL
)

Arguments

x

The text of the pdf file. This can be specified directly or the pdftools package is used to read the pdf file from a file path. To use the pdftools, the path argument must be set to TRUE.
path

An optional path designation for the location of the pdf to be converted to text. The pdftools package is used for this conversion.
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.
token_function

This is a function from the tokenizers package. Default is the tokenize_words function.

Value

A list of character vectors containing the tokens. More detail can be found looking at the documentation of the tokenizers package.

Examples

file <- system.file('pdf', '1610.00147.pdf', package = 'pdfsearch')
 convert_tokens(file, path = TRUE)

Format PDF input text

Description

Performs some formatting of pdf text upon import.

Usage

format_text(
  pdf_text,
  split_pdf = FALSE,
  remove_hyphen = TRUE,
  convert_sentence = TRUE,
  remove_equations = FALSE,
  split_pattern = "\\p{WHITE_SPACE}{3,}",
  ...
)

Arguments

pdf_text

A list of text from PDF import, most likely from 'pdftools::pdf_text()'. Each element of the list is a unique page of text from the PDF.
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 the following regex: "\([0-9]1,\)$", essentially this matches 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 "\pWHITE_SPACE3," which can be interpreted as: split based on three or more consecutive white space characters.
...

Additional arguments, currently not used.

Function to locate sections of pdf

Description

The ability to extract the location of the text and separate by sections. The function will return the headings with their location in the pdf.

Usage

heading_search(
  x,
  headings,
  path = FALSE,
  pdf_toc = FALSE,
  full_line = FALSE,
  ignore_case = FALSE,
  split_pdf = FALSE,
  convert_sentence = FALSE
)

Arguments

x

Either the text of the pdf read in with the pdftools package or a path for the location of the pdf file.
headings

A character vector representing the headings to search for. Can be NULL if pdf_toc = TRUE.
path

An optional path designation for the location of the pdf to be converted to text. The pdftools package is used for this conversion.
pdf_toc

TRUE/FALSE whether the pdf_toc function should be used from the pdftools package. This is most useful if the pdf has the table of contents embedded within the pdf. Must specify path = TRUE if pdf_toc = TRUE.
full_line

TRUE/FALSE indicating whether the headings should reside on their own line. This can create problems with multiple column pdfs.
ignore_case

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

Examples

file <- system.file('pdf', '1501.00450.pdf', package = 'pdfsearch')

heading_search(file, headings = c('abstract', 'introduction'),
  path = TRUE)

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,
  ...
)

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 the following regex: "\([0-9]1,\)$", essentially this matches 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 "\pWHITE_SPACE3," which can be interpreted as: 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.

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.

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)

Search a pdf file for keywords

Description

This uses the pdf_text from the pdftools package to perform keyword searches. Keyword locations indicating the line of the text as well as the page number that the keyword is found are returned.

Usage

keyword_search(
  x,
  keyword,
  path = FALSE,
  surround_lines = FALSE,
  ignore_case = FALSE,
  token_results = TRUE,
  heading_search = FALSE,
  heading_args = NULL,
  split_pdf = FALSE,
  remove_hyphen = TRUE,
  convert_sentence = TRUE,
  remove_equations = FALSE,
  split_pattern = "\\p{WHITE_SPACE}{3,}",
  ...
)

Arguments

x

Either the text of the pdf read in with the pdftools package or a path for the location of the pdf file.
keyword

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

An optional path designation for the location of the pdf to be converted to text. The pdftools package is used for this conversion.
surround_lines

numeric/FALSE indicating whether the output should extract the surrounding 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.
heading_search

TRUE/FALSE indicating whether to search for headings in the pdf.
heading_args

A list of arguments to pass on to the heading_search function. See heading_search for more details on arguments needed.
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 the following regex: "\([0-9]1,\)$", essentially this matches 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 "\pWHITE_SPACE3," which can be interpreted as: split based on three or more consecutive white space characters.
...

token_function to pass to convert_tokens function.

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.

Examples

file <- system.file('pdf', '1501.00450.pdf', package = 'pdfsearch')

keyword_search(file, keyword = c('repeated measures', 'mixed effects'),
  path = TRUE)
  
# Add surrounding text
keyword_search(file, keyword = c('variance', 'mixed effects'),
  path = TRUE, surround_lines = 1)
  
# split pdf
keyword_search(file, keyword = c('repeated measures', 'mixed effects'),
  path = TRUE, split_pdf = TRUE, remove_hyphen = FALSE)

Run Shiny Application Demo

Description

Function runs Shiny Application Demo

Usage

run_shiny()

Details

This function does not take any arguments and will run the Shiny Application. If running from RStudio, will open the application in the viewer, otherwise will use the default internet browser.