topic Re: How to multiply of two rasters in Python in Python Questions

How to multiply of two rasters in Python

LukaszB_ — Tue, 03 May 2011 23:47:21 GMT

How to multiply two rasters in Python?

I wrote script:
import arcpy
from arcpy import env
arcpy.CheckOutExtension('Spatial')
#folder with pixels: 0-bad and 1-good value
env.workspace = "B:\mask"
masks = arcpy.ListRasters("*", "")
#folder with value of pixels from 0 to 255
env.workspace = "B:\raster"
rastlist = arcpy.ListRasters("*", "")
for mask in masks:
    maskname = str(mask)
    for raster in rastlist:
        rastname = str(raster)
        if maskname[:25]==rastname[:25]:
          r= mask*raster
          env.workspace = "B:\MODIS\MOD15A2\converted\n"
          r.save(rastname)

But it doesn't multiply rasters. It is some problem with :
r= mask*raster
In Python window shows :

"Runtime error <type 'exceptions.TypeError'>: can't multiply sequence by non-int of type 'unicode'"

Re: How to multiply of two rasters in Python

JakeSkinner — Wed, 04 May 2011 10:56:26 GMT

The code above is attempting to multiply two strings together. I believe that is why you are receiving the error.

When multiplying rasters, try using the spatial analyst Times function. This will successfully multiply two rasters together.

Re: How to multiply of two rasters in Python

LukaszB_ — Wed, 04 May 2011 17:33:37 GMT

One more time thanks 🙂