Daniel,<br><br>Not sure if that fully satisfy with your requirements but I've already done a similar task with the following steps:<br><br>1. Create a point data source (with attributes) from your points for example by using <a href="http://www.gdal.org/ogr/drv_vrt.html">ogr_vrt</a>, something like:<br>
<br><OGRVRTDataSource><br> <OGRVRTLayer name="mypoints"><br> <SrcDataSource>ponts.csv</SrcDataSource> <br> <GeometryType>wkbPoint25D</GeometryType> <br> <GeometryField encoding="PointFromColumns" useSpatialSubquery="TRUE" x="lon83" y="lat83" z="attribute"/> <br>
</OGRVRTLayer><br></OGRVRTDataSource><br><br>2. Use <a href="http://www.gdal.org/gdal_grid.html">gdal_grid </a>to create an interpolated grayscale image from the point data dource.<br><br>3. To colorize the raster create (or compute) a LUT for each color band by containing the following information:<br>
<br><LUT>[src value 1]:[dest value 1],[src value 2]:[dest value 2],...</LUT><br><br>A template of this vrt should look like this:<br><br><VRTDataset rasterXSize="{RASTERXSIZE}" rasterYSize="{RASTERYSIZE}"><br>
<VRTRasterBand dataType="Byte" band="1"><br> <ColorInterp>Red</ColorInterp><br> <ComplexSource><br> <LUT>{LUT_RED}</LUT><br> <SourceFilename>{SOURCEFILE}</SourceFilename><br>
<SourceBand>1</SourceBand><br> <SrcRect xOff="{SRCXOFFSET}" yOff="{SRCYOFFSET}" xSize="{SRCXSIZE}" ySize="{SRCYSIZE}"/><br> <DstRect xOff="0" yOff="0" xSize="{RASTERXSIZE}" ySize="{RASTERYSIZE}"/><br>
</ComplexSource><br> </VRTRasterBand><br> <VRTRasterBand dataType="Byte" band="2"><br> <ColorInterp>Green</ColorInterp><br> <ComplexSource><br> <LUT>{LUT_GREEN}</LUT><br>
<SourceFilename>{SOURCEFILE}</SourceFilename><br> <SourceBand>1</SourceBand><br> <SrcRect xOff="{SRCXOFFSET}" yOff="{SRCYOFFSET}" xSize="{SRCXSIZE}" ySize="{SRCYSIZE}"/><br>
<DstRect xOff="0" yOff="0" xSize="{RASTERXSIZE}" ySize="{RASTERYSIZE}"/><br> </ComplexSource><br> </VRTRasterBand><br> <VRTRasterBand dataType="Byte" band="3"><br>
<ColorInterp>Blue</ColorInterp><br> <ComplexSource><br> <LUT>{LUT_BLUE}</LUT><br> <SourceFilename>{SOURCEFILE}</SourceFilename><br> <SourceBand>1</SourceBand><br>
<SrcRect xOff="{SRCXOFFSET}" yOff="{SRCYOFFSET}" xSize="{SRCXSIZE}" ySize="{SRCYSIZE}"/><br> <DstRect xOff="0" yOff="0" xSize="{RASTERXSIZE}" ySize="{RASTERYSIZE}"/><br>
</ComplexSource><br> </VRTRasterBand><br> <VRTRasterBand dataType="Byte" band="3"><br> <ColorInterp>Alpha</ColorInterp><br> <ComplexSource><br> <LUT>{LUT_ALPHA}</LUT><br>
<SourceFilename>{SOURCEFILE}</SourceFilename><br> <SourceBand>1</SourceBand><br> <SrcRect xOff="{SRCXOFFSET}" yOff="{SRCYOFFSET}" xSize="{SRCXSIZE}" ySize="{SRCYSIZE}"/><br>
<DstRect xOff="0" yOff="0" xSize="{RASTERXSIZE}" ySize="{RASTERYSIZE}"/><br> </ComplexSource><br> </VRTRasterBand><br></VRTDataset><br> <br>4. Use the <a href="http://www.gdal.org/gdal_vrttut.html">gdal vrt</a> driver (and <a href="http://www.gdal.org/gdal_translate.html">gdal_translate</a>) to create the final image (see an example attached). <br>
<br><br>Best regards,<br><br>Tamas<br><br><br><br><div class="gmail_quote">2011/2/23 Daniel Cole <span dir="ltr"><<a href="mailto:daniel@southernsolutionsms.com">daniel@southernsolutionsms.com</a>></span><br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div>I am a new mapserver user and have spent countless hours over the last month reading, trying code, etc. before posting here for help. I am trying to generate an image (non-interactive) on a webpage based off of attribute data in a points file. For example, 20 different points equally distributed in a field contain data about the moister level of the soil. I want to make the lowest levels blue and the highest levels yellow, or something like that with some gradients in between. If possible I want it to have interpolated data between them to show the gradual change, but that isn't a must. I also want to wrap it in a polygon that trims the edges. </div>
<div><br></div><div>I found some python code that I thought might do the trick , but it seems lots of heat maps are based off of how many points exist in a certain area, and thats now what I am doing. </div><div><br></div>
<div>My points contain numbers in the attributes, 5, 25, 92, 71, etc. I feel like I am missing some easy way to do this right in front of me with gdal or something. If someone has any direction or even demo code that would be greatly appreciated. </div>
<div><br></div><div>Thanks,<br><font color="#888888"><br>Daniel</font></div>
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