Similarity and Lucene

[Amin Mohammed-Coleman <am...@gmail.com>]

Hi

If I choose to subclass  the default similarity, do I need to apply the same
subclassed Similarity to IndexReader, IndexWriter and IndexSearcher?

I am interested in doing the below:

Similarity sim = new DefaultSimilarity() {
  public float lengthNorm(String field, int numTerms) {
    if(field.equals("body")) return (float) (0.1 * Math.log(numTerms));
    else return super.lengthNorm(field, numTerms);
  }
}

[taken from http://www.lucenetutorial.com/advanced-topics/scoring.html]

Is this approach advisable?


Cheers
Amin

Re: Similarity and Lucene

[Amin Mohammed-Coleman <am...@gmail.com>]

Allthough (I could be wrong) but I'm wondering if the lenthNorm is the
correct one I should be overriding.  I'm interested in the number of times a
term occurs found in a document (more occurance the higher the score) which
I believe is coord.  I may well be i am barking up the wrong tree.

Cheers
Amin

On Fri, Mar 20, 2009 at 4:20 PM, Amin Mohammed-Coleman <am...@gmail.com>wrote:

> Hi
>
> If I choose to subclass  the default similarity, do I need to apply the
> same subclassed Similarity to IndexReader, IndexWriter and IndexSearcher?
>
> I am interested in doing the below:
>
> Similarity sim = new DefaultSimilarity() {
>   public float lengthNorm(String field, int numTerms) {
>     if(field.equals("body")) return (float) (0.1 * Math.log(numTerms));
>     else return super.lengthNorm(field, numTerms);
>   }
> }
>
> [taken from http://www.lucenetutorial.com/advanced-topics/scoring.html]
>
> Is this approach advisable?
>
>
> Cheers
> Amin
>