David,
I have been following your stackoverflow posts, I understand what you
say, we decided to change the criteria and index an extra field (close
to your suggestion), so the sorting will happen now by polygon area desc
(Which induced another problem, calculation of polygon area on a
sphere), finally I got to the point of testing, also due to what you are
saying, is not a good idea to overload more than just the bare use of
points (Intersects) inside polygon to get the the list that matches
specific criteria.
To resume, calculate the "area of the polygon", again, for curved
polygons is not so obvious, do the standard solr search and sort by that
extra field, I guess solr overhead will be minimal in that case.
The real use case is for utility industry, let's say users have areas
where they get meter reads, readings are scheduled and assigned to the
users that contains such meter GPS location, some users might cover big
areas and possible to have smaller areas for other users inside such big
areas, so we changed the distance to center for area covered by, seemed
simpler and easier.
Thanks your response,
Guido.
On 16/04/13 15:06, Smiley, David W. wrote:
Guido,
The field type solr.SpatialRecursivePrefixTreeFieldType can only
participate in distance reporting for indexed points, not other shapes.
In fact, I recommend not attempting to get the distance if the field isn't
purely indexed points, as it may get confused if it seems some small
shapes. For your use-case, you should index an additional
solr.SpatialRecursivePrefixTreeFieldType field just for the points. You
could do this external to Solr, or you could write a Solr
UpdateRequestProcessor that parses the shape in order to then call
getCenter(), and put those points in the other field.
~ David
On 4/16/13 7:23 AM, "Guido Medina" <guido.med...@temetra.com> wrote:
Hi,
I got everything in place, my polygons are indexing properly, I played a
bit with LSP which helped me a lot, now, I have JTS 1.13 inside
solr.war; here is my challenge:
I have big polygon (A) which contains smaller polygons (B and C), B and
C have some intersection, so if I search for a coordinate inside the 3,
I would like to sort by the distance to the centre of the polygons that
match the criteria.
As example, let's say dot B is on the centre of B, dot C is at the
centre of C and dot A is at the intersection of B and C which happens to
be the centre of A, so for dot A should be polygon A first and so on. I
could compute with the distances using the result but since Solr is
doing a heavy load already, why not just include the sort in it.
Here is my field type definition:
<!-- Spatial field type -->
<fieldType name="location_rpt"
class="solr.SpatialRecursivePrefixTreeFieldType"
spatialContextFactory="com.spatial4j.core.context.jts.JtsSpatialContextFac
tory"
units="degrees"/>
Field definition:
<!-- JTS spatial polygon field -->
<field name="geopolygon" type="location_rpt" indexed="true"
stored="false" required="false" multiValued="true"/>
I'm using the Solr admin UI first to shape my query and then moving to
our web app which uses solrj, here is the XML form of my result which
includes the query I'm making, which scores all distances to 1.0 (Not
what I want):
|<?xml version="1.0" encoding="UTF-8"?>
<response>
<lst name="responseHeader">
<int name="status">0</int>
<int name="QTime">9</int>
<lst name="params">
<str name="fl">id,score</str>
<str name="sort">score asc</str>
<str name="indent">true</str>
<str name="q">*:*</str>
<str name="_">1366111120720</str>
<str name="wt">xml</str>
<str name="fq">{!score=distance}geopolygon:"Intersects(-6.271906
53.379284)"</str>
</lst>
</lst>
<result name="response" numFound="3" start="0" maxScore="1.0">
<doc>
<str name="id">uid13972</str>
<float name="score">1.0</float></doc>
<doc>
<str name="id">uid13979</str>
<float name="score">1.0</float></doc>
<doc>
<str name="id">uid13974</str>
<float name="score">1.0</float></doc>
</result>
</response>|
Thanks for all responses,
Guido.
