Raster Calculations with Spatial Analyst

JonathanHodel — Sat, 18 May 2013 11:33:48 GMT

I am trying to run NDVI calculations with Arcpy. My script is running but ArcGIS crashes each time I try to run it. Here is the part of the script with the problem:

for raster in rasterList:
        try:
                #Define the inputs
                arcpy.AddMessage('Calculating NDVI for ' + raster)
                NIR = raster + "\Band_1"
                Red = raster + "\Band_2"

                #Define outputs �?? Note: These will need to be deleted if you need to run this script again
                NIR_out = "NIR.tif"
                Red_out = "Red.tif"

                #Copy raster and map algebra �?? makes new rasters of Red and NearIR
                arcpy.AddMessage('exporting raster bands for calculation')
                arcpy.CopyRaster_management(NIR, NIR_out)
                arcpy.AddMessage('NIR band exported successfully')
                arcpy.CopyRaster_management(Red, Red_out)
                arcpy.AddMessage('Red band exported successfully')

                #Create Numerator and Denominator rasters as variables and NDVI output (note that arcpy.sa.Float returns a floating point raster)
                result = "NDVI.tif"
                NIRfloat = float(NIR)
                Redfloat = float(Red)
                Num = Raster(NIRfloat) - Raster(Redfloat)

Re: Raster Calculations with Spatial Analyst

DanPatterson_Retired — Sat, 18 May 2013 12:46:19 GMT

I am assuming you imported the spatial analyst.
float should be capitalized
what of the arcpy.AddMessage lines get displayed?

topic Raster Calculations with Spatial Analyst in Data Management Questions

Raster Calculations with Spatial Analyst

Re: Raster Calculations with Spatial Analyst