The MEDLINE N-gram Set 2022: by Split, Group, Filter, and Combine Algorithm

The MEDLINE n-gram set (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 with more than 50 characters or the total word count is less than 30. The specifications of generating these n-grams are listed as follows:

  • MEDLINE: 2022 - TI and AB (from MEDLINE Baseline Repository - MBR, pubmed22nXXXX.xml -> PmidTiAbS22nXXXX.txt: 1 ~ 1114)
  • Method: Split, Combine, Filter Algorithm
  • Max. Character Size: 50
  • Min. word count: 30
  • Min. document count: 1

  • Total document count: 33,405,863
  • Total sentence count: 224,228,682
  • Total token count: 4,680,725,429

  • N-gram files
    • File format - 3 fields:
      Document countWord countN-gram
    • Sorted by document count, word count, then alphabetic order of n-grams. N-gram set is not sorted. It can be sorted by nGramUtil package.

  • Download:
    N-gramsFileZip SizeActual SizeNo. of n-grams
    Unigrams1-gram.2022.tgz8.4 MB21 MB1,248,727
    Bigrams2-gram.2022.tgz55 MB161 MB7,519,422
    Trigrams3-gram.2022.tgz86 MB284 MB11,046,633
    Four-grams4-gram.2022.tgz62 MB217 MB7,142,084
    Five-grams5-gram.2022.tgz31 MB111 MB3,133,905
    N-gram SetnGramSet.2022.30.tgz241 MB792 MB30,090,771
    Distilled N-gram SetdistilledNGram.2022.tgz97 MB315 MB11,949,720