: The piece I was also missing as well was to add:
: <queryParser name="functionparser"
: class="org.apache.solr.search.FunctionQParserPlugin"/>
a) the FunctionQParserPlugin is already registered by default using hte
name "func" -- you shouldn't need to register it explicitly unless you
want to use it with a custom name.
b) the FunctionQParserPlugin is not even required in order to use
"FunctionRangeQParserPlugin" (aka: "frange") that Rafał suggested for
filtering by function range...
: > fq={!frange l=0 u=100}sum(fielda, fieldb, fieldc)
-Hoss
