Ferret talk - Mar 2008 - Which field(s) matched?

Is there a way to discover which fields in a document matched the search 
that was performed?

I''ve just started with Ferret, but so far I can only get back the ids
of
the documents that were matched (along with the score).

I''m aware there is a highlighting method, but I was hoping for
something
computer readable (unless I''m misunderstanding what data can be gained 
from that method).

Thanks
-Rob

Robert Hulme wrote:
> Is there a way to discover which fields in a document matched the search 
> that was performed?
> 
> I''ve just started with Ferret, but so far I can only get back the
ids of
> the documents that were matched (along with the score).
> 
> I''m aware there is a highlighting method, but I was hoping for
something
> computer readable (unless I''m misunderstanding what data can be
gained
> from that method).
I''ve implemented a field_scores hash that can be returned along with
each document and aggregate score. It''s only currently working in
Ferret 0.11.4.

> I''ve implemented a field_scores hash that can be returned along
with
> each document and aggregate score. It''s only currently working in
> Ferret 0.11.4.
Could you please give a code example of how to do a query and get the 
field_scores hash?

I have Ferret 0.11.6.

-Rob

Robert Hulme wrote:
>> I''ve implemented a field_scores hash that can be returned
along with
>> each document and aggregate score. It''s only currently working
in
>> Ferret 0.11.4.
> Could you please give a code example of how to do a query and get the 
> field_scores hash?
> 
> I have Ferret 0.11.6.
Rob, FerretResult objects are given a ferret_field_scores attribute,
which is an array (not a hash, as I said above) of field_score objects,
in order of decreasing score. Field_score objects have "field" and
"score" attributes.

You specify which fields you want to see the field scores for by adding
the field_info option :field_score => :yes.

You can use field_scores to display an extract of the field that best
matches the user''s query:

@result.highlight @query, :field => @result.ferret_field_scores.first.field

It''d take some work to port it to Ferret 0.11.6, though I will do
this soon.