Thanks guys...
I'm using edismax, and I have a long bf field, that I want in a solr's
requesthandler config as default, but customizable via query string,
something like that:
<requestHandler>
<lst name="defaults">
<str name="bf">product(a,$a)^$fa sum(b,$b1,$b2)^$fb c^$fc ...</str>
where the caller would pass $a, $fa, $b1, $b2, $fb, $fc (and a, b, c are
numeric fields)
So my problem is with $fa, $fb, and $fc. Solr doesn't take that syntax.
For numeric operands, is the dismax boost operator ^ just a pow()? If
so, my problem is solved by doing that:
<str name="bf">pow(product(a,$a1),$fa) pow(sum(b,$b1,$b2),$fb)
pow(c,$fc)</str>
Is a^b equiv to pow(a,b)?
Thanks,
Olivier
On 7/14/2015 2:31 PM, Chris Hostetter wrote:
To clarify the difference:
- "bf" is a special param of the dismax parser, which does an *additive*
boost function - that function can be something as simple as a numeric
field
- alternatively, you can use the "boost" parser in your main query string,
to wrap any parser (dismax, edismax, standard, whatever....) in a
*multiplicitive* boost, where the boost function can be anything
- multiplicitve boosts are almost always what people really want, additive
boosts are a lot less useful.
- when specifying any function, you can use variable derefrencing for any
function params.
So in the example Upayavira gave, you can use any arbitrary query param to
specify the function to use as a multiplicitive boost arround an arbitrary
query -- which could still use dismax if you want (just specify the
neccessary parser "type" as a localparam on the inner query, or use a
defType localparam on the original boost query). Or you could explicitly
specify a function that incorporates a field value with some other
dynamic params, and use that entire function as your multiplicitive boost.
a more elaborate example using the "bin/solr -e techproducts" data...
http://localhost:8983/solr/techproducts/query?debug=query&q={!boost%20b=$boost_func%20defType=dismax%20v=$qq}&qf=name+title&qq=apple%20ipod&boost_func=pow%28$boost_field,$boost_factor%29&boost_field=price&boost_factor=2
"params":{
"qq":"apple ipod",
"q":"{!boost b=$boost_func defType=dismax v=$qq}",
"debug":"query",
"qf":"name title",
"boost_func":"pow($boost_field,$boost_factor)",
"boost_factor":"2",
"boost_field":"price"}},
: Date: Tue, 14 Jul 2015 21:58:36 +0100
: From: Upayavira <u...@odoko.co.uk>
: Reply-To: solr-user@lucene.apache.org
: To: solr-user@lucene.apache.org
: Subject: Re: Dereferencing boost values?
:
: You could do
:
: q={!boost b=$b v=$qq}
: qq=your query
: b=YOUR-FACTOR
:
: If what you want is to provide a value outside.
:
: Also, with later Solrs, you can use ${whatever} syntax in your main
: query, which might work for you too.
:
: Upayavira
:
: On Tue, Jul 14, 2015, at 09:28 PM, Olivier Lebra wrote:
: > Is there a way to do something like this: " bf=myfield^$myfactor " ?
: > (Doesn't work, the boost value has to be a direct number)
: >
: > Thanks,
: > Olivier
:
-Hoss
http://www.lucidworks.com/
