Word frequency statistics for a file

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Tip 1531 Printable Monobook Previous Next

created 2007 · complexity basic · author vale.smth · version 7.0


This tip shows how to generate a table of occurrence frequencies for every word in the current buffer, or in selected text. For example, the results may include the following which shows that "action" was used 12 times, "agree" 7 times, and so on:

action  12
agree   7
and     26

[edit] Using a dictionary

Procedure:

  • In Vim, copy the code shown below, then enter :@" to execute it (or put the code in your vimrc).
  • Press V then move the cursor to select the lines whose words you want to count.
  • Alternatively, select no lines, in which case all words in the buffer will be counted.
  • Type :WordFrequency and press Enter.

A new window will open with a scratch buffer showing the word frequencies.

function! WordFrequency() range
  let all = split(join(getline(a:firstline, a:lastline)), '\A\+')
  let frequencies = {}
  for word in all
    let frequencies[word] = get(frequencies, word, 0) + 1
  endfor
  new
  setlocal buftype=nofile bufhidden=hide noswapfile tabstop=20
  for [key,value] in items(frequencies)
    call append('$', key."\t".value)
  endfor
  sort i
endfunction
command! -range=% WordFrequency <line1>,<line2>call WordFrequency()


[edit] Most frequent words first

Putting the code below in your .vimrc and entering :WordFrequency will show you the most frequent words first. For example:

count 	 words
--------------------------
37	 the
23	 a
21	 set
17	 in let
14	 to
13	 call line
11	 of for word

In this example the word "set" occurred 21 times in the text and the words "call" and "line" both occurred 13 times.

Code:

" Sorts numbers in ascending order.
" Examples:
" [2, 3, 1, 11, 2] --> [1, 2, 2, 3, 11]
" ['2', '1', '10','-1'] --> [-1, 1, 2, 10]
function! Sorted(list)
  " Make sure the list consists of numbers (and not strings)
  " This also ensures that the original list is not modified
  let nrs = ToNrs(a:list)
  let sortedList = sort(nrs, "NaturalOrder")
  echo sortedList
  return sortedList
endfunction

" Comparator function for natural ordering of numbers
function! NaturalOrder(firstNr, secondNr)
  if a:firstNr < a:secondNr
    return -1
  elseif a:firstNr > a:secondNr
    return 1
  else 
    return 0
  endif
endfunction

" Coerces every element of a list to a number. Returns a new list without
" modifying the original list.
function! ToNrs(list)
  let nrs = []
  for elem in a:list
    let nr = 0 + elem
    call add(nrs, nr)
  endfor
  return nrs
endfunction

function! WordFrequency() range
  " Words are separated by whitespace or punctuation characters
  let wordSeparators = '[[:blank:][:punct:]]\+'
  let allWords = split(join(getline(a:firstline, a:lastline)), wordSeparators)
  let wordToCount = {}
  for word in allWords
    let wordToCount[word] = get(wordToCount, word, 0) + 1
  endfor

  let countToWords = {}
  for [word,cnt] in items(wordToCount)
    let words = get(countToWords,cnt,"")
    " Append this word to the other words that occur as many times in the text
    let countToWords[cnt] = words . " " . word
  endfor

  " Create a new buffer to show the results in
  new
  setlocal buftype=nofile bufhidden=hide noswapfile tabstop=20

  " List of word counts in ascending order
  let sortedWordCounts = Sorted(keys(countToWords))

  call append("$", "count \t words")
  call append("$", "--------------------------")
  " Show the most frequent words first -> Descending order
  for cnt in reverse(sortedWordCounts)
    let words = countToWords[cnt]
    call append("$", cnt . "\t" . words)
  endfor
endfunction

command! -range=% WordFrequency <line1>,<line2>call WordFrequency()

[edit] Using commands

The following alternative demonstrates the amazing power of Ex commands. This process replaces the current buffer with a word frequency table, so you should be working on a copy of your text.

Enter the following commands. In the third line, the "^A" represents Ctrl-A which needs to be entered by pressing Ctrl-V then Ctrl-A (if you use Ctrl-V for paste, press Ctrl-Q then Ctrl-A):

:%s/\_A\+/\t1\r/g
:sort i
:g/^\c\(.\+\)\n\1$/norm! $yiwj@"^Akdd

The first command replaces all sequences of not-word characters (including newlines, \_A\+) with "\t1\r" (a tab character, the digit 1, and a newline). The result leaves only words, each followed by a count of 1, with a single word per line.

The second command sorts the lines, ignoring case. The next step combines all lines containing the same word ignoring case.

The third command uses :g/// to flag each line which is followed by another line containing the same text (\1), ignoring case (\c). The given normal-mode command is then executed on each flagged line: $ moves to end-of-line, yiw copies inner word (the count); j goes down one line; @" effectively types the contents of the unnamed register (count copied from previous line), and that value is a repeat count for the Ctrl-A which increments the 1 that many times to accumulate the total; k goes up one line; dd deletes that line.

Possible mods:

  • use a more general substitute pattern for non-English texts: :%s/\%(\K\@!\_.\)\+/\t1\r/g
    This will keep all 'iskeyword' characters (except digits) instead of only letters.
  • at the end, add a command to sort after the counts: :sort! n /\t/
    ! - reverse sort, n - sort after numbers, /\t/ - only look at text right from the first Tab character

[edit] Comments

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