Strange no data values -3,4028234663

[GIS_Administratorat_RWE]

Hi,

when interpolating points to raster using arcpy I get strange values (-3,4028234663) for no data pixels. If I interpolate the same points with same method in Desktop I get NoData values. How could I get rid of these strange values and just have the "no data"? Any ideas?

Thanks a lot

Felix

[DanPatterson_Retired]

Your code would be useful and what environments you set within your code to control the results

[GIS_Administratorat_RWE]

Hi Dan,

I use the following lines to compile the interpolate from point features I have created from txt using

     ...

     arcpy.ASCII3DToFeatureClass_3d(inTXT, inFormat, outFC, outType, zFactor, CS, inputRes, fileSuffix, decSep)

     arcpy.AddZInformation_3d(outFC, "Z", "NO_FILTER") ==> outFC is the point FC

     arcpy.env.mask=outFC
     arcpy.env.nodata="NONE"

     # --- Interpolate surface
     outSurfaceTile = OUTRASTERWSP + str("/SPLINE_") + fClass + ".tif"
     outSurface = arcpy.sa.NaturalNeighbor(outFC,"Z",inputRes)
     outSurface.save(outSurfaceTile)

     arcpy.CalculateStatistics_management(outSurfaceTile)
     arcpy.BuildPyramids_management(outSurfaceTile) ==> this output shows the strange no data values
     outHS = OUTRASTERWSP + "/HS_" + fClass + ".tif"
     outHillshade=arcpy.sa.Hillshade(outSurface,135,45,"NO_SHADOWS")
     outHillshade.save(outHS) ==> this output shows nodata as no data values
     arcpy.BuildPyramids_management(outHS)

The strange thing is, that the only the result of the interpolation shows the strange values and the hillshade compile from that shows the normal "nodata" as no data values..

Thanks

Felix

[DanPatterson_Retired]

perhaps it is the explicit setting of arcpy.env.nodata NoData (Environment setting)—Help | ArcGIS for Desktop since it doesn't seem to affect final results and things are as they should be when done through arcmap, I would see what removing or changing the settings on this has

[GIS_Administratorat_RWE]

Hi Dan,

I have started without this env. setting - doesn't work as well..

Cheers

Felix

[DanPatterson_Retired]

before after you deleted pyramids and statistics? once they are created, they should be removed before trying something else

[curtvprice]

I would try saving to Esri grid format instead of .tif first.