thats what it does. its more like a computed field. and you can sort by more than one of them.
please see the JIRA issue for a description of the differences between function queries. On Fri, Sep 20, 2013 at 10:49 AM, Shai Erera <[email protected]> wrote: > Yes, you're right, but that's unrelated to this thread. I passed > doScore=true and the scores come out the same, meaning Expression didn't > affect the actual score, only the sort-by value (which is ok). > > search Expression > doc=1, score=0.37158427, field=0.7431685328483582 > doc=0, score=0.37158427, field=0.3715842664241791 > > Shai > > > On Fri, Sep 20, 2013 at 5:10 PM, Robert Muir <[email protected]> wrote: >> >> On Fri, Sep 20, 2013 at 8:01 AM, Shai Erera <[email protected]> wrote: >> > >> > Expression >> > I tried the new module, following TestDemoExpression and compiled the >> > expression using this code: >> > >> > Expression expr = JavascriptCompiler.compile("_score * boost"); >> > SimpleBindings bindings = new SimpleBindings(); >> > bindings.add(new SortField("_score", SortField.Type.SCORE)); >> > bindings.add(new SortField("boost", SortField.Type.LONG)); >> > >> > The result scores are: >> > >> > search Expression >> > doc=1, score=NaN, field=0.7431685328483582 >> > doc=0, score=NaN, field=0.3715842664241791 >> > >> > As you can see, both CustomScoreProvider and Expression methods return >> > same >> > scores for the docs, while the FunctionQuery method returns different >> > scores. The reason is that when using FunctionQuery, the scores of the >> > ValueSources are multiplied by queryWeight, which seems correct to me. >> > >> > Expression is more about sorting than scoring as far as I understand >> > (for >> > instance, the result FieldDocs.score is NaN) >> >> Why does that come as a surprise to you? Pass true to indexsearcher >> to get the documents score back here. >> >> ======================= Release 2.9.0 2009-09-23 ======================= >> >> Changes in backwards compatibility policy >> >> LUCENE-1575: Searchable.search(Weight, Filter, int, Sort) no longer >> computes a document score for each hit by default. >> ... (Shai Erera via Mike McCandless) >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [email protected] >> For additional commands, e-mail: [email protected] >> > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
