topic Re: Raster Calculator ArcMap Python in Python Questions

Raster Calculator ArcMap Python

Yaseen_TahaMustafa — Sat, 11 Dec 2021 17:07:58 GMT

Hi All,
I am trying to do some calculation on Raster using raster calculator in python. I have several restaer and I implemented the calculation using loop. I was working well when I was using ArcMap 9, and now I am using version 10.7. but it gives some errors. The code is below:

import sys, string, os, arcgisscripting, math, arcpy
from arcpy import env
from arcpy.sa import *
gp = arcgisscripting.create()
gp.OverWriteOutput = 1
gp.CheckOutExtension("spatial")
arcpy.CheckOutExtension("spatial")
gp.AddToolbox("C:/Program Files (x86)/ArcGIS/Desktop10.7/ArcToolbox/Toolboxes/Spatial Analyst Tools.tbx")
gp.workspace = "E:/JASTTpaperWork/Data/Processed/TIFF/"
out_workspace = "E:/JASTTpaperWork/Data/Processed/TIFF/ArcGIS02"
InMask = "E:/JASTTpaperWork/Data/Shapefile/KRG.shp"
# Get a list of grids in the workspace.
rasters = gp.ListRasters("","TIF")
raster = rasters.next()
while raster:
    print raster
    raster = rasters.next()
rasters.reset()
raster = rasters.next()
print gp.GetMessages()
while raster:
    # Set local variables
    InRaster =  raster
    # Set the outputname for each output to be the same as the input.
    OutRaster = out_workspace + "/" + raster
    InExpression ="Con("+ InRaster +" <=  - 1,0,"+ InRaster +")"
    arcpy.gp.RasterCalculator_sa(InExpression, OutRaster)
    gp.CheckOutExtension("Spatial")
    print raster
    #print InExpression
    raster = rasters.next()
    # If an error occurred while running a tool, then print the messages.
    print gp.GetMessages()‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Any help would be highly appreciated.

Re: Raster Calculator ArcMap Python

DanPatterson_Retired — Tue, 17 Mar 2020 11:44:51 GMT

The errors?

Re: Raster Calculator ArcMap Python

Yaseen_TahaMustafa — Tue, 17 Mar 2020 11:47:05 GMT

Sorry the errors are:

Traceback (most recent call last):
File "E:/JASTTpaperWork/Data/testetstetstetstsCON.py", line 27, in <module>
arcpy.gp.RasterCalculator_sa(InExpression, OutRaster)
File "C:\Program Files (x86)\ArcGIS\Desktop10.7\ArcPy\arcpy\geoprocessing\_base.py", line 510, in <lambda>
return lambda *args: val(*gp_fixargs(args, True))
ExecuteError: Failed to execute. Parameters are not valid.
ERROR 000989: Python syntax error: Parsing error SyntaxError: invalid syntax (line 1)

Re: Raster Calculator ArcMap Python

Anonymous User — Sat, 11 Dec 2021 17:08:00 GMT

Looks like its the '/'. Place an 'r' in the beginning to declare it a raw string and change slashes to be backslashes throughout the code-

gp.workspace = r"E:\JASTTpaperWork\Data\Processed\TIFF"
out_workspace = r"E:\JASTTpaperWork\Data\Processed\TIFF\ArcGIS02"‍‍‍‍

It also looks like you are checking out 'spatial' twice. A little bit of code to help with checking out licenses:

if arcpy.CheckExtension("Spatial) == "Available":
    arcpy.AddMessage("Checking out {} licence".format(extlicense))
    # Check out the extension if available
    arcpy.CheckOutExtension(extlicense)
else:
    # If extension is not available
    arcpy.AddMessage("!!!! Failed !: {}".format(arcpy.GetMessages(0)))
    sys.exit(0)


# And then return it when you're done:‍‍‍‍‍‍‍‍‍‍‍
arcpy.CheckInExtension("Spatial")‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Raster Calculator ArcMap Python

DanPatterson_Retired — Tue, 17 Mar 2020 12:07:06 GMT

could be

Raster Calculator—Help | Documentation

Note:
The Raster Calculator tool is not intended to be used in scripting environments and is not available in the standard Spatial Analyst ArcPy module. To learn more about scripting and Map Algebra, see the help topic What is Map Algebra? in the Spatial Analyst extension help.

You will probably have to implememt 'Con' directly

Con—Help | Documentation

Re: Raster Calculator ArcMap Python

DanPatterson_Retired — Tue, 17 Mar 2020 12:09:32 GMT

Forward slashes are valid path separators. Raw encoding, double back slashes or single forward slashes will be parsed properly. Folders with spaces or characters other than letters and numbers and the underscore are iffy.

Re: Raster Calculator ArcMap Python

Anonymous User — Tue, 17 Mar 2020 12:32:26 GMT

My bad. I'm used to raw encoding and coding backslashes and forget sometimes.

Line 8 does have that iffyness ... 'C:\Program Files (x86)\ArcGIS\Desktop10.7\'...

Re: Raster Calculator ArcMap Python

Yaseen_TahaMustafa — Tue, 17 Mar 2020 12:33:09 GMT

Dear Jeffy and Dan, Thanks for the quick response. I have followed your response and double checked each line of the cod. however I got the same error.

Any suggestions please

Re: Raster Calculator ArcMap Python

DanPatterson_Retired — Tue, 17 Mar 2020 12:36:11 GMT

so you replaced the raster calculator and implemented Con directly from the spatial analyst tools (see the Note

Re: Raster Calculator ArcMap Python

Yaseen_TahaMustafa — Tue, 17 Mar 2020 12:54:56 GMT

Actully I did not get the point.

I exported the python code from module builder and Iater expanded the code through reading and exporting the rasters. So I do not know what do you mean.

Re: Raster Calculator ArcMap Python

DanPatterson_Retired — Tue, 17 Mar 2020 15:44:59 GMT

It means you can't use modelbuilder. The link that I provided is for the Con tool and you can use it directly instead of through a raster calculator expression. See the code example in the link

Re: Raster Calculator ArcMap Python

Yaseen_TahaMustafa — Tue, 17 Mar 2020 19:14:18 GMT

Thanks but I cannot see the link that you sent.... Could you please send the link.....

Re: Raster Calculator ArcMap Python

DanPatterson_Retired — Tue, 17 Mar 2020 19:17:43 GMT

In the ArcMap help, search on Con... these are for ArcGIS Pro, but the help topic is the same

Con—Help | Documentation

Conditional evaluation with Con—Help | Documentation

Re: Raster Calculator ArcMap Python

Yaseen_TahaMustafa — Tue, 17 Mar 2020 19:18:28 GMT

Thanks for the prompt response

Re: Raster Calculator ArcMap Python

DavidPike — Sat, 11 Dec 2021 17:08:03 GMT

import arcpy
import os


arcpy.CheckOutExtension("Spatial")


arcpy.env.workspace = r"E:/JASTTpaperWork/Data/Processed/TIFF/"
out_workspace = r"E:/JASTTpaperWork/Data/Processed/TIFF/ArcGIS02"

InMask = r"E:/JASTTpaperWork/Data/Shapefile/KRG.shp"

# Get a list of grids in the workspace.
rasters = arcpy.ListRasters("","TIF")

for raster in rasters:

    # Set the outputname for each output to be the same as the input.
    output_path = os.path.join(out_workspace,raster)

    #create raster object
    raster_path = os.path.join(arcpy.env.workspace,raster)
    raster_object = arcpy.Raster(raster_path)

    #return conditional raster
    con_raster = Con(raster_object <= -1, 0, raster_object)
    
    #save it
    con_raster.save(output_path)

arcpy.CheckInExtension("Spatial")

def ty(name):
    return print("Thanks" + name)

ty("Dave")
    ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Raster Calculator ArcMap Python

Yaseen_TahaMustafa — Wed, 18 Mar 2020 07:51:17 GMT

Dear David,
Thanks for the your genourus help. I tried to run the cond but I got an error as shown below:

Traceback (most recent call last):
File "E:\JASTTpaperWork\Data\ExtRasCal - Copy.py", line 23, in <module>
raster_object = raster(raster_path)
TypeError: 'unicode' object is not callable

I search online about this error but still I cannot figure out how to solve it.

Any suggestion.....!

Re: Raster Calculator ArcMap Python

DavidPike — Wed, 18 Mar 2020 10:11:35 GMT

I've changed this to arcpy.Raster

if that doesn't work try arcpy.Raster(raster)

Re: Raster Calculator ArcMap Python

Yaseen_TahaMustafa — Sat, 11 Dec 2021 17:08:07 GMT

Thank you for the reply. The previous error is gone after I tried your suggestion, and added some library in the top. the code is below:

importarcpy, sys, string, arcgisscripting, math, arcpy
importos
fromarcpy import env
fromarcpy.sa import *
gp = arcgisscripting.create()


arcpy.CheckOutExtension("Spatial")


arcpy.env.workspace = r"E:\\JASTTpaperWork\\Data\\Processed\\TIFF\\"
out_workspace = r"E:\\JASTTpaperWork\\Data\\Processed\\TIFF\\ArcGIS02\\"

InMask = r"E:\\JASTTpaperWork\\Data\\Shapefile\\KRG.shp"

# Get a list of grids in the workspace.
rasters = arcpy.ListRasters("","TIF")

for raster in rasters:

# Set the outputname for each output to be the same as the input.
output_path = os.path.join(out_workspace,raster)

#create raster object
raster_path = os.path.join(arcpy.env.workspace,raster)
raster_object = arcpy.Raster(raster_path)
print output_path
#return conditional raster
con_raster = Con(raster_object <= -1, 0, raster_object)

#save it
con_raster.save(output_path)

arcpy.CheckInExtension("Spatial")

def ty(name):
return print("Thanks" + name)

ty("Dave")‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

However, this time another error appears which it seems to be a problem with the path of saving the data. The error is:

Traceback (most recent call last):
File "E:\JASTTpaperWork\Data\ExtRasCal - Copy.py", line 32, in <module>
con_raster.save(output_path)
RuntimeError: ERROR 000875: Output raster: E:\JASTTpaperWork\Data\Processed\TIFF\ArcGIS02\2000_EVI.tif's workspace is an invalid output workspace.

Any dvice....!

Re: Raster Calculator ArcMap Python

DavidPike — Wed, 18 Mar 2020 18:01:08 GMT

Try hardcoding a different path as the out workspace. look at your path formatting and check against examples in the esri help.

There's no need to keep adding those modules - sys, string, arcgisscripting, math. it just slows down your process.

Re: Raster Calculator ArcMap Python

Yaseen_TahaMustafa — Sat, 11 Dec 2021 17:08:10 GMT

Fine .... I rechecked the code and I change the path of the out workspace. The error is still there and I an really frustrating. The error message is:

Traceback (most recent call last):
  File "E:\JASTTpaperWork\Data\ExtRasCal - Copy.py", line 35, in <module>
    con_raster.save(output_path)
RuntimeError: ERROR 010240: Could not save raster dataset to 2000_EVI.tif with output format TIFF.‍‍‍‍

Assist please.....