OK this is the code I am using right now for testing:
//"B" shapefile
EnhancedMapLayer hazard = (EnhancedMapLayer)context.getLayer(1);
FeatureSource fsh = hazard.getFeatureSource();
//"A" shapefile
EnhancedMapLayer asset = (EnhancedMapLayer)context.getLayer(2);
FeatureSource fsa = asset.getFeatureSource();
FilterFactory filterFactory =
FilterFactoryFinder.createFilterFactory();
String hgeometryName = fsh.getSchema().getDefaultGeometry().getName();
String ageometryName = fsa.getSchema().getDefaultGeometry().getName();
AttributeExpression hgeometryExpression =
filterFactory.createAttributeExpression(hgeometryName);
AttributeExpression ageometryExpression =
filterFactory.createAttributeExpression(ageometryName);
GeometryFactory geometryFactory = new GeometryFactory();
GeometryFilter geoFilter =
filterFactory.createGeometryFilter(FilterType.GEOMETRY_INTERSECTS);
geoFilter.addLeftGeometry(hgeometryExpression);
geoFilter.addRightGeometry(ageometryExpression);
FeatureCollection fch = fsh.getFeatures(geoFilter);
The FilterType will actually change depending on the nature of the features in
A and B. For this example I am using INTERSECTS because A features are lines
and B features are POLYGONS.
(For points, I've been trying to use DWITHIN, with little success.)
I don't see how I can map the elements of the resulting collection of B
features to A features, and then apply the next filter.
Thanx!
gaby
***************************************************************
** Gabriella Turek [EMAIL PROTECTED] **
** National Institute of Water & Atmospheric Research (NIWA) **
** PO Box 8602 Christchurch New Zealand +64-3-343-8067 **
***************************************************************
>>>Jody Garnett <[EMAIL PROTECTED]> 12/11/07 12:19 pm >>>
Yes; although it amounts to setting up your geometry filter to match
your definition of "near". What is your definition of near?
Cheers,
Jody
>Is there any way to skip the loop in step (2)?
>gaby
>
>
>>>>Jody Garnett <[EMAIL PROTECTED]> 12/11/07 11:02 am >>>
>>>>
>When you get back the feature collection of those things "near" to A;
>you can call the Collection_Max function on the featurecollection
>directly; this is way faster (and may be optimzied into SQL if your
>datastore is backed by SQL):
>
>-
>http://docs.codehaus.org/display/GEOTDOC/10+FeatureCollection+Aggregate+Functions
>
>
>Cheers,
>Jody
>
>Gabriella Turek wrote:
>
>>I have two shape files, call them A and B. I need to:
>>(1) find out the features in B that are "near" to each feature in A.
>>(2) Interrogate an attribute value of these "near" features and pick the
>>highest value.
>>
>>I actually figured out how to do it, but I don't think I am doing it "right",
>>i.e. using all the tools
>>at my disposal.
>>
>>My steps are:
>>(1) creat up geometry filter to find features in B close to A
>>(2) loop thru each feature in A to find these "near" B features
>>(3) when one is found, interrogate attribute value and establish if it's a
>>new max
>>
>>I get the nagging feeling that I dont' need to do this looping and that -
>>moreover - I can
>>have yet another filter which looks for my max value. I've tried a few things
>>with little success.
>>Any help will be greatly appreciated.
>>Gaby
>>
>>
>>
>>
>>** Gabriella Turek [EMAIL PROTECTED]
>>** National Institute of Water & Atmospheric Research (NIWA)
>>** PO Box 8602 Christchurch New Zealand +64-3-343-8067
>>
>>
>>
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