[mapserver-users] Is kerneldensity_attribute implemented?

Rahkonen Jukka (Tike) jukka.rahkonen at mmmtike.fi
Thu Oct 23 01:21:03 PDT 2014


Hi,

Fine, I could make is work with this knowledge. Is it so that the only documentation right now is in the RFC and main documentation page http://mapserver.org/documentation.html  does not know about dynamic heatmaps yet? Might be worth having an own entry in the Output section.

I was trying to normalize my source data. There seems to be some limited possibilities for doing that with source layer and kerneldensity layer:
- In source LAYER the attribute to be used for weighting can be selected with "STYLE SIZE [attribute] END. The [attribute] is selected as it stands and no expressions can be used in STYLE - SIZE
- In the kerneldensity LAYER " processing "KERNELDENSITY_NORMALIZATION" can be used for normalizing data by a multiplication factor.
- For more advanced normalization it must be done in the data because for example expression [POPULATION]/[AREA] can't be resolved on-the-fly because expressions are not supported in STYLE - SIZE.

Have I understood right? With some sources of the point layer data there could perhaps be a workaround by computing new field on-the-fly inside LAYER - DATA: "select geometry, population/area as popar from source" and by using then "popar" as size attribute. I made some trials with connnectiontype OGR but it was not trivial to make my selection to work from  a shapefile.

-Jukka Rahkonen-

thomas bonfort wrote:

> Jukka,
> All the functionality is tested in msautotest, the KERNELDENSITY_ATTRIBUTE is
> an error is the RFC. To use an attribute use STYLE SIZE [attribute] END in your
> linked vector layer.
> 
> --
> thomas
> 
> On 23 October 2014 06:55, Rahkonen Jukka (Tike)
> <jukka.rahkonen at mmmtike.fi> wrote:
> > Hi,
> >
> > I have tried to use attribute based weights in heatmaps as in RFC 108
> > example http://mapserver.org/development/rfc/ms-rfc-108.html
> > processing "KERNELDENSITY_ATTRIBUTE=POP2010"
> >
> > However, this processing option does not seem to have any affect. It is not
> used in the MS autotest mapfile and I wonder if it has been implemented at all
> yet. Does somebody know?
> >
> > -Jukka Rahkonen-
> > _______________________________________________
> > mapserver-users mailing list
> > mapserver-users at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/mapserver-users


More information about the MapServer-users mailing list