14 lines
785 B
Markdown
14 lines
785 B
Markdown
#ml #учеба [[data mining]]
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![[Pasted image 20260719174012.png]]
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Main function to reduce word to it's original (root) form - stem (lemma).
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### Lovins stemmer
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Rules only, remove suffixes, main problem is over removal of suffixes the, those, them - the, love - lov and so on.
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### Porter stemmer
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Classify characters as vowels and consonant. Group sequential v and c and remove them by some rules (have rules, so still have some errors) Implementation in nltk.
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### Snowball stemmer
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Updated porter with new rules, stop word and including other languages (including Russian) also have stop words list, such as _the_, _a_, _being_, and the like. Also has implementation in nltk.
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Source: https://www.ibm.com/think/topics/stemming?regionCode=us&languageCode=en&cm-history=us-en
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