The MEDLINE N-gram Set 2016: 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: 2016 - TI and AB (from MEDLINE Baseline Repository - MBR, PmidTiAbS16nXXXX.txt: 1 ~ 812)
• Method: Split, Combine, Filter Algorithm
• Max. Character Size: 50
• Min. word count: 30
• Min. document count: 1

• Total document count: 24,358,442
• Total sentence count: 143,471,776
• Total token count: 2,971,013,236

• N-gram files
  • File format - 3 fields:

    Document count

    Word count

    N-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-grams	File	Zip Size	Actual Size	No. of n-grams
  Unigrams	1-gram.2016.tgz	5.9 MB	15 MB	883,287
  Bigrams	2-gram.2016.tgz	37 MB	109 MB	5,114,547
  Trigrams	3-gram.2016.tgz	55 MB	182 MB	7,134,807
  Four-grams	4-gram.2016.tgz	38 MB	132 MB	4,380,474
  Five-grams	5-gram.2016.tgz	18 MB	64 MB	1,812,223
  N-gram Set	nGramSet.2016.30.tgz	153 MB	499 MB	19,325,338
  Distilled N-gram Set	distilledNGram.2016.tgz	60 MB	191	7,402,848