topic Re: Point To Raster Tool in Geoprocessing Questions

Point To Raster Tool

MichaelBlom — Thu, 05 Jun 2014 14:35:59 GMT

Hello,

I am using the point to raster tool, summing by "theCalcField", and using a cell size of .85 degrees. So I expect a full blocky-style raster.

Why then does the tool create a raster as though each cell is considering values from outside it's own cell (as per many other spatial analyst tools)?

This is my command.
arcpy.PointToRaster_conversion(LOCATIONS, theCalcField, RASTER_LAYER, "SUM", "NONE", "0.85")

And an image of the raster:

[ATTACH=CONFIG]34391[/ATTACH]

Re: Point To Raster Tool

JimCousins — Thu, 05 Jun 2014 15:03:52 GMT

At .85 degrees, this should be 2 or 3 cells tall, correct? So the cellsize is not being set correctly. Is the input point data in geographic coordinate system?
Regards,
Jim

Re: Point To Raster Tool

MichaelBlom — Thu, 05 Jun 2014 15:19:02 GMT

Hmmm,

I think a degree at the equator should be approximately 69 miles (111 kilometers)

so, .85 of a degree maybe around 100km... and where in my image it is blocky (in the bottom left), this block size is about 100km, so that is the expected cell size.

the whole raster should be cells of this size, I would think, according to how point to raster works.

Re: Point To Raster Tool

JimCousins — Fri, 06 Jun 2014 14:11:38 GMT

Perhaps your layer display is using bilinear interpolation?

Re: Point To Raster Tool

MichaelBlom — Fri, 06 Jun 2014 15:14:03 GMT

Hi Jim,

Nice one! yes, it was due to the symbology that had been applied to the raster.

Thanks very much!