Ferret talk - Apr 2007 - Count frequency of term in a specific document?

Is there any way to count the frequency of specific term in one
document?
I can''t find any method... Do you?

-- 
Posted via http://www.ruby-forum.com/.

On 4/6/07, James Kim <sjoonk at gmail.com> wrote:
> Is there any way to count the frequency of specific term in one
> document?
> I can''t find any method... Do you?
Hi James,

Caleb and I answered your previous post but here is my answer again.

You can find the frequency without storing term-vectors. Simply use
the TermDocEnum and skip to the document you are interested.

 tde = index.reader.term_docs_for(:field, ''term'')
 tde.skip_to(100)

 # now check that we are at the correct document. If there are no
 # instances of ''term'' in document 100 then it will skip to
the next
 # document with an instance of the term ''term''
 frequency = tde.doc == 100 ? tde.freq : 0
 puts "frequency of field:term in document 100 is #{frequency}"

Here is a full working example;

   require ''rubygems''
   require ''ferret''

   index = Ferret::I.new
   index << ''one''
   index << ''one two one three one four one'' # doc 1
   index << ''one''
   index << ''no 1s''                          # doc 3
   index << ''one''

   def get_frequency(index, doc_num, term, field = :id)
     tde = index.reader.term_docs_for(field, term)
     tde.skip_to(doc_num)
     return tde.doc == doc_num ? tde.freq : 0
   end

   puts get_frequency(index, 1, ''one'') #=> 4
   puts get_frequency(index, 3, ''one'') #=> 0
-- 
Dave Balmain
http://www.davebalmain.com/

Thanks!

One more. I''d like to count all term''s frequency on a specific
document.
Upper solution is for count one term''s frequency. Is there any way to
gather all term''s frequency of a specific document?

-- 
Posted via http://www.ruby-forum.com/.

On 4/7/07, James Kim <sjoonk at gmail.com> wrote:
>
> Thanks!
>
> One more. I''d like to count all term''s frequency on a
specific document.
> Upper solution is for count one term''s frequency. Is there any way
to
> gather all term''s frequency of a specific document?
Yes, for this you need to store term-vectors with positions. That will
allow you to count the frequency of all terms in the document.

-- 
Dave Balmain
http://www.davebalmain.com/