lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Kainth, Sachin" <Sachin.Kai...@atkinsglobal.com>
Subject RE: categorisation
Date Fri, 09 Feb 2007 10:40:30 GMT
It makes sense to me only if you tell me that all the bits in the BitSet
"all" will be 1. 

-----Original Message-----
From: Erik Hatcher [mailto:erik@ehatchersolutions.com] 
Sent: 08 February 2007 18:37
To: java-user@lucene.apache.org
Subject: Re: categorisation


On Feb 8, 2007, at 12:36 PM, Kainth, Sachin wrote:

> Chris has given an example of how to perform categorisation of lucene 
> searches:
>
> String[] mfgs = ...;
>   String query = "+category:cameras +price:[0 to 10]";
>   Query q = QueryParser.parse(query);
>   Hits results = searcher.search(q, mySort)
>   BitSet all = (new QueryFilter(q)).bits(reader)
>   int[] mfg_counts = new int[mfgs.length];
>   for i in (0 to mfgs.length) {
>      BitSet these = (new QueryFilter(new TermQuery("mfg",mfgs 
> [i]))).bits(reader);
>      these.and(all)
>      mfg_counts[i] = these.cardinality();
>   }
>
> What I don't understand though is what this line does:
>
> BitSet all = (new QueryFilter(q)).bits(reader)
>
> Anyone have any ideas?

"all" is a BitSet lit up for the documents that matched "query".   
"these" (the BitSet for a particular category) is .anded with "all"  
to get the counts _left over_ for each category given "query".

Make sense?

	Erik


---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org



This message has been scanned for viruses by MailControl - (see
http://bluepages.wsatkins.co.uk/?4318150)


This email and any attached files are confidential and copyright protected. If you are not
the addressee, any dissemination of this communication is strictly prohibited. Unless otherwise
expressly agreed in writing, nothing stated in this communication shall be legally binding.

The ultimate parent company of the Atkins Group is WS Atkins plc.  Registered in England No.
1885586.  Registered Office Woodcote Grove, Ashley Road, Epsom, Surrey KT18 5BW.

Consider the environment. Please don't print this e-mail unless you really need to. 

---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org


Mime
View raw message