ngram

Extracts ngram bag of words around words that match a search pattern. 
Note: If an input contains the search pattern twice, only the ngram bag of words of the last hit is detected. Consider individual text splitting with text2sentences() or strsplit2() before applying ngram().

Provides a function collection to extract metadata, sectioned text and study characteristics from scientific articles in 'NISO-JATS' format. Articles in PDF format can be converted to 'NISO-JATS' with the 'Content ExtRactor and MINEr' ('CERMINE', <https://github.com/CeON/CERMINE>). For convenience, two functions bundle the extraction heuristics: JATSdecoder() converts 'NISO-JATS'-tagged XML files to a structured list with elements title, author, journal, history, 'DOI', abstract, sectioned text and reference list. study.character() extracts multiple study characteristics like number of included studies, statistical methods used, alpha error, power, statistical results, correction method for multiple testing, software used. An estimation of the involved sample size is performed based on reports within the abstract and the reported degrees of freedom within statistical results. In addition, the package contains some useful functions to process text (text2sentences(), text2num(), ngram(), strsplit2(), grep2()). See Böschen, I. (2021) <doi:10.1007/s11192-021-04162-z> Böschen, I. (2021) <doi:10.1038/s41598-021-98782-3> and Böschen, I (2023) <doi:10.1038/s41598-022-27085-y>.

Ingmar Böschen

JATSdecoder

A Metadata and Text Extraction and Manipulation Tool Set

ngram function

<dl><dt>x</dt>
<dd>vector of text strings to process.</dd>
<dt>pattern</dt>
<dd>a search term pattern to extract the ngram bag of words.</dd>
<dt>ngram</dt>
<dd>a vector of length=2 that defines the number of words to extract from left and right side of pattern match.</dd>
<dt>tolower</dt>
<dd>Logical. If TRUE converts text and pattern to lower case.</dd>
<dt>split</dt>
<dd>Logical. If TRUE splits text input at "[.,;:] " before processing. Note: You may consider other text splits before.</dd>
<dt>exact</dt>
<dd>Logical. If TRUE only exact word matches will be proceses</dd></dl>

Arguments

ngram — ngram

<dl>

<dt>x</dt>
<dd>vector of text strings to process.</dd>


<dt>pattern</dt>
<dd>a search term pattern to extract the ngram bag of words.</dd>


<dt>ngram</dt>
<dd>a vector of length=2 that defines the number of words to extract from left and right side of pattern match.</dd>


<dt>tolower</dt>
<dd>Logical. If TRUE converts text and pattern to lower case.</dd>


<dt>split</dt>
<dd>Logical. If TRUE splits text input at "[.,;:] " before processing. Note: You may consider other text splits before.</dd>


<dt>exact</dt>
<dd>Logical. If TRUE only exact word matches will be proceses</dd>

</dl>

ngram: ngram

Description

Usage

Value

Arguments

Examples