classification doesn't work with floating points

[Steven M. Ottens]

Hi all,

I'm working on a dynamic classification application which works with 
SLD. I select a bounding box and Mapserver generates a new SLD with the 
minimum and maximum values and a range of classes between. This works 
fine and the SLD is correct with all the expected classes. However if I 
use that SLD to generate a new map I only see 3 colours instead of the 
expected 50.
After some investigation I discovered that it was due to the very small 
classes I get:
<ColorMapEntry color="#0c317c" quantity="-6.75" />
<ColorMapEntry color="#0f377c" quantity="-6.54" />
<ColorMapEntry color="#0f407e" quantity="-6.47" />
<ColorMapEntry color="#11497f" quantity="-6.40" />
<ColorMapEntry color="#12527f" quantity="-6.36" />
<ColorMapEntry color="#145a81" quantity="-6.32" />
<ColorMapEntry color="#166482" quantity="-6.29" />
<ColorMapEntry color="#186c83" quantity="-6.27" />
<ColorMapEntry color="#1a7584" quantity="-6.25" />
<ColorMapEntry color="#1c7e85" quantity="-6.24" />
<ColorMapEntry color="#1d8786" quantity="-6.23" />
<ColorMapEntry color="#1f9087" quantity="-6.22" />
<ColorMapEntry color="#219888" quantity="-6.21" />
<ColorMapEntry color="#239e89" quantity="-6.20" />
<ColorMapEntry color="#26a380" quantity="-6.19" />
<ColorMapEntry color="#2caa74" quantity="-6.18" />
<ColorMapEntry color="#31b068" quantity="-6.17" />
<ColorMapEntry color="#36b75c" quantity="-6.16" />
<ColorMapEntry color="#3cbe50" quantity="-6.15" />
<ColorMapEntry color="#42c444" quantity="-6.14" />
<ColorMapEntry color="#48cb38" quantity="-6.13" />
<ColorMapEntry color="#4dd12c" quantity="-6.12" />
<ColorMapEntry color="#53d81f" quantity="-6.11" />
<ColorMapEntry color="#58de14" quantity="-6.10" />
<ColorMapEntry color="#5ee508" quantity="-6.09" />
<ColorMapEntry color="#61e901" quantity="-6.08" />
<ColorMapEntry color="#72ea01" quantity="-6.07" />
<ColorMapEntry color="#8bed02" quantity="-6.06" />
<ColorMapEntry color="#a2f002" quantity="-6.05" />
<ColorMapEntry color="#b9f102" quantity="-6.04" />
<ColorMapEntry color="#d1f402" quantity="-6.02" />
<ColorMapEntry color="#e9f602" quantity="-6.01" />
<ColorMapEntry color="#fcf803" quantity="-5.99" />
<ColorMapEntry color="#faf105" quantity="-5.97" />
<ColorMapEntry color="#f6e808" quantity="-5.94" />
<ColorMapEntry color="#f3de0c" quantity="-5.90" />
<ColorMapEntry color="#f0d50f" quantity="-5.85" />
<ColorMapEntry color="#eccc13" quantity="-5.75" />
<ColorMapEntry color="#e9c316" quantity="-5.63" />
<ColorMapEntry color="#000000" quantity="-5.52" />
<ColorMapEntry color="#e2b01c" quantity="-5.35" />
<ColorMapEntry color="#ff1b1b" quantity="-5.00" />
<ColorMapEntry color="#ffa720" quantity="350.00" />

If the classes are without floats there's no problem and mapserver works 
as expected.
Some more investigation showed that the 3 colours I see are the ones from:
<ColorMapEntry color="#0f377c" quantity="-6.54" />
<ColorMapEntry color="#000000" quantity="-5.52" />
<ColorMapEntry color="#ff1b1b" quantity="-5.00" />
The last being the class everything bigger then -5.
It's striking that the other two are both around the .5, which does make 
me believe there's something wrong with the floating point handling of 
mapserver with regard of drawing maps. Is there a setting in my mapfile 
which I have to set to make sure it will use all decimals to do the 
rendering?

I've attached the map file of this particular layer. In there you see 
multiple layers with the same classification, each is an aggregation of 
the previous one and kicks in at a different scale level. The whole 
thing is a detailed DEM of the Netherlands.

Regards,
Steven


-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: hoogte.map
URL: <http://lists.osgeo.org/pipermail/mapserver-users/attachments/20070426/25cc22ff/attachment.ksh>