1

I am trying a convert a raster dataset [a simple 4 x 4] into a numpy array using RasterToNumPyArray. Here is my sample raster dataset:

Sample Raster Dataset

RasterToNumPyArray however, returns zero for Null values:

inRaster = "Slope_NULL"

# Create a Raster Object and get its lowerleft
aRObject = arcpy.Raster(inRaster)
lowerLeft = aRObject.extent.lowerLeft

print aRObject.noDataValue

# Create a numpy array of the Raster Object
anArray = arcpy.RasterToNumPyArray(aRObject) 
print anArray

and I get:

enter image description here

I am wondering if there is a way that I could get None or NaN instead of zero in my array?

I know I can change the Nodata to a value using nodata_to_value, however, RasterToNumPyArray syntax is explaining that the default value is None, and it is important for me to have None and not zeros in my array.

How can I have None or NaN [I am not sure which one is better supported in numpy] in my array?

3
  • there is a nodata parameter in RasterToNumpy, discussed here: gis.stackexchange.com/q/217775/46073 Nov 12 '18 at 21:07
  • @AndreasMüller Yes, it has a parameter "nodata_to_value" which convert nodata to a value. If it is not set it converts nodata to zero as I showed in my example.
    – sMartines
    Nov 13 '18 at 22:59
  • @Hornbydd Would you please take a look at this question?
    – sMartines
    Nov 13 '18 at 23:36
1

I think what you are looking for is NAN in Numpy module:

import numpy as np
arcpy.RasterToNumPyArray(inRaster, nodata_to_value= np.NAN)

Also see for here for other constants defined in Numpy.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.