kernel density in ArcGIS API for Python - how do I work with the results?

04-28-2022 03:02 PM
Occasional Contributor III

I'm trying to run arcgis.raster.functions.gbl.kernel_density (link to docs). I think I'm running it ok, but I have no idea what to do with the output! The docs just say you get an output raster, no samples included, and even Google search doesn't turn up much. 

I create an input like this: 


from arcgis import GIS
import arcgis
gis = GIS(profile="AGOL")
points_item = gis.content.get('abcdefg123456...')
points_fl = arcgis.features.FeatureLayer(points_item)



I tried running kernel density with the feature layer points_fl, but it only works if I use points_item as the input. That seems odd, but it works, or at least it stops giving me an error.  Here is what I'm trying:


out_raster = arcgis.raster.functions.gbl.kernel_density(
    points_item, '<fieldname>', cell_size=1000, search_radius=2000, 
    area_unit_scale_factor='SQUARE_MAP_UNITS', out_cell_values='DENSITIES', 
    method='PLANAR', in_barriers=None)



I have confirmed that the Kernel Density GP tool in Pro works with this data set and these settings, so my inputs and parameters are valid as far as I can tell. If I do a type(out_raster), I get arcgis.raster._layer.ImageryLayer. With any attempt to find out about this raster, I get an error. Something as simple as trying to print out_raster.raster_info gives my a lengthy traceback, but this is the crux of it: 

Exception: Invalid or missing input parameters.
Authentication token required. (status code 499).
(Error Code: 400)

Same for trying to access the columns or rows properties, which seem like pretty basic things you should be able to find out about a raster. Interestingly, if I try this in an AGOL notebook where I definitely should be signed in, I get the same error. 

Can anyone tell me how to work with kernel density output and what I can do with it? So far, I just know kernel density ran and didn't fail, but have no idea how to do anything with the output. 


Side note: I am also unable to run the function. I also get a large traceback, but the main error is "RuntimeError: Unable to create service". I think I am just missing a role to create imagery services or something, because I lack any option to create them in Pro or on the AGOL website. I'm going to work on that before I worry about this part of it...






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