[
https://issues.apache.org/jira/browse/TEXT-155?focusedWorklogId=210669&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-210669
]
ASF GitHub Bot logged work on TEXT-155:
---------------------------------------
Author: ASF GitHub Bot
Created on: 10/Mar/19 13:36
Start Date: 10/Mar/19 13:36
Worklog Time Spent: 10m
Work Description: aherbert commented on issue #109: TEXT-155: Add a
generic OverlapSimilarity measure
URL: https://github.com/apache/commons-text/pull/109#issuecomment-471306795
I have tried to clean up the history into a single commit.
I have changed the name back to `IntersectionSimilarity` as it was pointed
out to me that `Overlap` has a specific meaning in the combinatorics on words
space, an “overlap” is a specific repeated pattern. Also there is an
[OverlapCoefficient](https://en.wikipedia.org/wiki/Overlap_coefficient) between
sets which is the intersection over the min size of the two sets.
I dropped the computation of the metrics and the union from the
`IntersectionResult`. This class now has no logic but just holds data.
I removed the use of streams and use a classic iteration over the smaller of
the two sets of keys to get the intersection.
This is now a generic set similarity which just requires a function to split
up a `CharSequence`. A place to provide such functions, as contained in the
example units test, is best left to another block of new functionality.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
Issue Time Tracking
-------------------
Worklog Id: (was: 210669)
Time Spent: 4h 50m (was: 4h 40m)
> Add a generic OverlapSimilarity measure
> ---------------------------------------
>
> Key: TEXT-155
> URL: https://issues.apache.org/jira/browse/TEXT-155
> Project: Commons Text
> Issue Type: New Feature
> Affects Versions: 1.6
> Reporter: Alex D Herbert
> Priority: Minor
> Fix For: 1.7
>
> Time Spent: 4h 50m
> Remaining Estimate: 0h
>
> The {{SimilarityScore<T>}} interface can be used to compute a generic result.
> I propose to add a class that can compute the intersection between two sets
> formed from the characters. The sets must be formed from the {{CharSequence}}
> input to the {{apply}} method using a {{Function<CharSequence, Set<T>>}} to
> convert the {{CharSequence}}. This function can be passed to the
> {{SimilarityScore<T>}} during construction.
> The result can then be computed to have the size of each set and the
> intersection.
> I have created an implementation that can compute the equivalent of the
> {{JaccardSimilary}} class by creating {{Set<Character>}} and also the
> F1-score using bigrams (pairs of characters) by creating {{Set<String>}}.
> This relates to
> [Text-126|https://issues.apache.org/jira/projects/TEXT/issues/TEXT-126] which
> suggested an algorithm for the Sorensen-Dice similarity, also known as the
> F1-score.
> Here is an example:
> {code:java}
> // Match the functionality of the JaccardSimilarity class
> Function<CharSequence, Set<Character>> converter = (cs) -> {
> final Set<Character> set = new HashSet<>();
> for (int i = 0; i < cs.length(); i++) {
> set.add(cs.charAt(i));
> }
> return set;
> };
> IntersectionSimilarity<Character> similarity = new
> IntersectionSimilarity<>(converter);
> IntersectionResult result = similarity.apply("something", "something else");
> {code}
> The result has the size of set A, set B and the intersection between them.
> This class was inspired by my look through the various similarity
> implementations. All of them except the {{CosineSimilarity}} perform single
> character matching between the input {{CharSequence}}s. The
> {{CosineSimilarity}} tokenises using whitespace to create words.
> This more generic type of implementation will allow a user to determine how
> to divide the {{CharSequence}} but to create the sets that are compared, e.g.
> single characters, words, bigrams, etc.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
