String metric

In <a href="/facts/Mathematics/pxTouaz4">mathematics</a> and <a href="/facts/Computer_science/lN3pEyPz">computer science</a>, a string metric (also known as a string similarity metric or string distance function) is a <a href="/facts/Metric_(mathematics)/RkUptSo8">metric</a> that measures <a href="/facts/Distance/hbXlaEFk">distance</a> ("inverse similarity") between two <a href="/facts/String_(computer_science)/4ChJu5WS">text strings</a> for <a href="/facts/Approximate_string_matching/aotktvNI">approximate string matching</a> or comparison and in <a href="/facts/Approximate_string_matching/aotktvNI">fuzzy string searching</a>. A requirement for a string metric (e.g. in contrast to <a href="/facts/String_matching/RCvwDRle">string matching</a>) is fulfillment of the <a href="/facts/Triangle_inequality/KubLjkwr">triangle inequality</a>. For example, the strings "Sam" and "Samuel" can be considered to be close. A string metric provides a number indicating an algorithm-specific indication of distance.
The most widely known string metric is a rudimentary one called the <a href="/facts/Levenshtein_distance/F0otyNSl">Levenshtein distance</a> (also known as edit distance). It operates between two input strings, returning a number equivalent to the number of substitutions and deletions needed in order to transform one input string into another. Simplistic string metrics such as <a href="/facts/Levenshtein_distance/F0otyNSl">Levenshtein distance</a> have expanded to include phonetic, <a href="/facts/Token_(parser)/T1JYWpIf">token</a>, grammatical and character-based methods of statistical comparisons.
String metrics are used heavily in <a href="/facts/Information_integration/veGbc8F7">information integration</a> and are currently used in areas including <a href="/facts/Data_analysis_techniques_for_fraud_detection/P5mE7yxW">fraud detection</a>, <a href="/facts/Fingerprint_analysis/5WLcd20T">fingerprint analysis</a>, <a href="/facts/Plagiarism_detection/3lXBIVGK">plagiarism detection</a>, <a href="/facts/Ontology_merging/HG5DKY8j">ontology merging</a>, <a href="/facts/DNA_analysis/H21wH0ze">DNA analysis</a>, RNA analysis, <a href="/facts/Image_analysis/woLB8cX7">image analysis</a>, evidence-based <a href="/facts/Machine_learning/e0w0XJTu">machine learning</a>, <a href="/facts/Database/VYcpkevb">database</a> <a href="/facts/Data_deduplication/sHuJ8zya">data deduplication</a>, <a href="/facts/Data_mining/AH53q5ac">data mining</a>, <a href="/facts/Incremental_search/1cn56QBk">incremental search</a>, <a href="/facts/Data_integration/BU47JR28">data integration</a>, <a href="/facts/Malware/5ee7TLFR">malware detection</a>, and semantic <a href="/facts/Knowledge_integration/ua0vKvJj">knowledge integration</a>.

String metric open-in-new

String metric