countREG

countREG is a method for enumerating occurrences of patterns defined by regular expressions within a text corpus. Used in corpus linguistics, data cleaning, and content analysis, it provides a compact summary of how often predefined patterns appear across documents or within sections of text.

Operation and outputs: Users supply a collection of regular expressions and a text source. For each expression, the tool scans the text and increments a counter whenever a match is found. Outputs include a per-pattern count, a per-document count, and optional normalized statistics such as frequency per thousand words. Some implementations also report the total number of matches, the proportion of documents containing at least one match, and the distribution of match lengths.

Variants and performance: countREG can run in a single-pass streaming mode for memory efficiency or in a batch mode for richer diagnostics. It may support overlapping matches, case sensitivity options, Unicode handling, and capturing groups to refine what is counted. Performance optimizations include precompiling expressions, indexing, and parallel processing.

Applications and considerations: Typical uses include tracking linguistic features (for example, specific token types or markers), monitoring compliance with formatting rules, and estimating content prevalence in large corpora. It is often used alongside other text-analysis steps such as tokenization and normalization. Limitations include the potential for overcounting with overlapping patterns or ambiguous boundaries, and the possibility of missing semantically meaningful instances that do not match provided patterns. Users should carefully design expressions and validate results against annotated data.

See also: regular expressions, text mining, pattern matching, corpus analysis.