Hi
I am trying to figure out how to create weighted heat maps by performing a
vector to raster transformation on my data via the SLD gs:Heatmap function (
http://docs.geoserver.org/stable/en/user/styling/sld-extensions/rendering-transform.html).
So far I have successfully created weighted heat maps using Geoserver, WMS,
and SLD, but the generated heat maps are not exactly as I would like them
because the data in the underlying transformed raster seems to always get
scaled to values between 0 and 1 before the ColorMap is applied.
I very much want to create images that look like a heat map, but I do not
always want my data to scale between 0 and 1. For instance, say my
weighted attribute has a theoretical maximum of 100, but the attribute
values never exceed 50 (for a certain data set). In this hypothetical
case, I would want the data to get scaled to between 0 and 0.5 - because I
wouldn't want the colors from the ColorMap that represent a value near 1 to
be displayed.
So far, it seems like no matter what I try the data always dynamically gets
scaled to be between 0 and 1 - meaning that I always get the colors at the
top end of the ColorMap even if this is not what I want. I should note
that I have looked at the Barnes Surface transformation, and I am pretty
convinced that I cannot achieve the same heat map look and feel using that
transformation.
My questions are:
1) in the SLD is there a way to set a theoretical range of values for the
weighted attribute so that the underlying data gets scaled based upon that
range?
2) if there is not a way to scale the data appropriately in the SLD, is
there another approach or another transformation I could use that would
generate an image that looks like the heat map images?
3) if I have to code up a solution in Java, what GeoTools classes should I
use? Pointing me to some help documentation with examples would be great.
I have seen some people suggest using VectorToRasterProcess.java, but I
don't know if that is a good approach.
Thanks in advance,
B
I am using the weightAttr parameter in my SLD, and that seems to work;
however, the generated heat maps seem to always scale the underlying
weighted data to values between 0 and 1.
I want to generate heat maps using Geoserver, WMS and SLD. I have been
able to successfully generate heat maps this way, but the generated heat
maps are not quite what I want them to be.
I want my heat maps to be weighted by an attribute
My questions are:
- is there a way I can get the ColorMap to not
- if I cannot do what I want using Geoserver, does anyone have a suggestion
for what GeoTools methods to use to create heat maps?
Barnes Surface
weightAttr
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