Run raster calculation on multiple lists of rasters

Anonymous User

So I'm having a little trouble here...This is part of a larger script and I can get everything to work up until this point.

I have an equation I need to throw in the Raster Calculator:

((DEM - MIN) / (MAX - MIN) * 100)


I need to perform this equation 6 times (I have 6 DEMs, 6 Mins, and 6 Maxes numbered in ascending order in the gdb).  What I was hoping to do was set up an equation where I can do something like this:

# List 3 raster types for input for raster calculator demlist = arcpy.ListRasters('DEM_ext*') minlist = arcpy.ListRasters('ZonalMin*') maxlist = arcpy.ListRasters('ZonalMax*')

From this list I would then like to use this equation in the raster calculator:

# Starting from the first raster of each type and iterate through to the sixth [0] - [5]  # Start at index [0]    expression = ((demlist[0] - minlist[0]) / (maxlist[0] - minlist[0])* 100)  # Then go to [1] and so on... outrast = outpath + os.sep + 'Relative_elv' + str(index)  # index here is a variable to represent a raster in the list RasterCalculator(expression, outrast)  # index += 1 

I would like this to iterate through and perform this same calculation on all 6 rasters (DEM, MIN, MAX).  I have been trying to figure out a way but I am at a loss as to how to do this? What would be a good way to initiate a loop to go through and perform this calculation?  Thanks.


This is what each list of rasters looks like:
[ATTACH=CONFIG]17386[/ATTACH]

window.PNG

Snag_1967316.png

curtvprice

The Raster Calculator is designed for use as a tool or in ModelBuilder.
You'd do well to do this task in Python map algebra instead.

For example, use Raster() to cast them to type Raster so the map algebra will work.

from arcpy.sa import *  arcpy.workspace = path  # direct where the input and output is  # list inputs demlist = arcpy.ListRasters('DEM_ext*') minlist = arcpy.ListRasters('ZonalMin*') maxlist = arcpy.ListRasters('ZonalMax*')  # Starting from the first raster of each type and iterate through to the sixth [0] - [5] # Start at index [0]    for k in range(6): # 0,1,2... 5     outrast = 100.0 * ((Raster(demlist) - Raster(minlist)) / \                     (Raster(maxlist) - Raster(minlist))        outrastName = 'Rel_elv%s' % k # grid names should be < 13 chars     outrast.save(outrastName)