The MEDLINE N-gram Set by Split, Group, Filter, and Combine Algorithm

The MEDLINE n-gram set - 2014 (generated by split, group, filter, and combine algorithm) is listed as bellows. For each MEDLINE record, title and abstract are used as the source of n-grams. They are combined, tokenized into sentences, and then tokenized into tokens (words use space as word boundary). Finally, n-grams are generated by filtering out terms have than 50 characters or the total word count is less than 30. The specifications of generating these n-grams are listed as follows:

  • MEDLINE: 2014 - TI and AB (from PmidTiAbS14nXXXX.txt: 1 ~ 746)
  • Method: Split, Combine, Filter Algorithm
  • Max. Character Size: 50
  • Min. word count: 30
  • Min. document count: 1

  • Total document count: 22,356,869
  • Total sentence count: 126,612,705
  • Total token count: 2,610,209,406

  • N-gram files
    • File format - 3 fields:
      Document countWord countN-gram
    • Sorted by document count, word count, then alphabetic order of n-grams.

    Download:

    N-gramsFileZip SizeActual SizeNo. of n-grams
    Unigrams1-gram.2014.tgz5.4MB14MB804,382
    Bigrams2-gram.2014.tgz33MB98MB4,587,349
    Trigrams3-gram.2014.tgz49MB160MB6,287,536
    Four-grams4-gram.2014.tgz33MB114MB3,799,377
    Five-grams5-gram.2014.tgz15MB54MB1,545,175
    N-gram SetnGramSet.2014.30.tgz170MB437MB17,023,819
    Distilled N-gram SetdistilledNGram.2014.tgz51MB164MB6,351,392