topic Re: How to set the spatial reference when saving raster function output? in ArcGIS API for Python Questions

How to set the spatial reference when saving raster function output?

DavidJohnson5 — Tue, 29 Dec 2020 23:47:50 GMT

Can I reproject the output of a raster function before saving it to a GIS?

For example, this code applies an agricultural mask to a burnt area.

burnt_areas_masked = colormap(set_null(rasters=[ag_mask, burnt_areas]),
colormap=[[4, 115, 76, 0],
[3, 168, 112, 0],
[2, 230, 152, 0],
[1, 255, 170, 0]])

The inputs 'ag_mask' and 'burnt_areas' are in-memory rasters generated by raster functions applied to imagery layer items in the GIS. The output 'burnt_areas_mask' inherits the spatial reference of 'ag_mask'. I guess this makes sense since 'ag_mask' is the first raster in the list of inputs. But 'ag_mask' is only a boolean layer and not actual the input data. So I need a way to set the spatial reference of the output 'burnt_areas_mask' to the spatial reference of 'burnt_areas'.

The "reproject" function looks like a possible solution.

https://developers.arcgis.com/python/api-reference/arcgis.raster.functions.html#reproject

But I get a "name error" when I try to call it.

Any suggestions?

Re: How to set the spatial reference when saving raster function output?

DanPatterson — Wed, 30 Dec 2020 00:59:13 GMT

Don't do the * import thing until you check

import arcgis.raster.functions as arf dir(arf) [... 'reproject', ...] # ---- then arf.reproject(....

Re: How to set the spatial reference when saving raster function output?

Rhea_Jackson — Wed, 30 Dec 2020 07:20:52 GMT

Hi David,

reproject function was added only in V1.8.3. Please check if you are using an older version.

You can also try using out_spatial_reference env variable

Re: How to set the spatial reference when saving raster function output?

DanPatterson — Wed, 30 Dec 2020 12:13:49 GMT

Which probably means you arent using Pro 2.7 or didn't do a

> conda update arcgis

through conda or the package manager.

More details...

ArcGIS API For Python | ArcGIS for Developers

Re: How to set the spatial reference when saving raster function output?

DavidJohnson5 — Wed, 30 Dec 2020 20:35:15 GMT

I should have mentioned that I'm using ArcGIS Online Notebooks. I'm not sure what version of the API it uses. But it must be an earlier version since reproject is not available. I tried your second suggestion Rhea to set the out_spatial_reference property and that worked. Thanks Dan and Rhea for the quick responses!

Re: How to set the spatial reference when saving raster function output?

DanPatterson — Wed, 30 Dec 2020 22:25:42 GMT

@DavidJohnson5

import arcgis arcgis.__version__ '1.8.3'

for version number