topic Re: Troubles in a tool using multiprocessing in ArcGIS API for Python Questions

Troubles in a tool using multiprocessing

AzusaIshizaki — Thu, 07 Jun 2018 08:39:17 GMT

Hello,

I am developing a tool to clip raster from a large raster within an arbitrary range from some points.

The number of points is more than 20000, it's enormous.

So, I tried to use multiprocessing in python.

I created a python program.

However, it doesn't work completely.

I tested this python program for 10 points.

Then, 6 out of 10 points were outputted correctly.

On the other hand, 4 points were outputted as empty tables, not rasters.

I guess causes as below ...

(1) Time out of arcpy.Clip_management

(2) Access to one raster from some process

But I can't find any solution.

I attached python file.

If anyone knows of any solution, give me advice or solutions.

Thanks,

Re: Troubles in a tool using multiprocessing

JoshuaBixby — Thu, 07 Jun 2018 14:58:24 GMT

Since you are using ArcPy and not the ArcGIS API for Python, I am sharing this with Python‌.

Re: Troubles in a tool using multiprocessing

DanPatterson_Retired — Thu, 07 Jun 2018 23:13:43 GMT

You mention points, then clip. are you trying to get raster values for those points?

If so, then maybe Extract Multi Values to Points

Re: Troubles in a tool using multiprocessing

AzusaIshizaki — Fri, 08 Jun 2018 00:07:19 GMT

No. I mention points, then clip raster in a rectangular area around a mentioned point.

The number of mentioned points are more than 20000.

Re: Troubles in a tool using multiprocessing

DanPatterson_Retired — Fri, 08 Jun 2018 00:17:36 GMT

Ok, so you create a feature class (temporary?) or extract by an extent then?

Which means that you might be able to set the analysis extent (an environment setting) and save the result out as a raster without any clipping.

Perhaps an image of a portion of the area would help even if to confirm that the extents of the bounds are overlapping the raster.

Re: Troubles in a tool using multiprocessing

AzusaIshizaki — Fri, 08 Jun 2018 00:56:24 GMT

Using the extracted raster from a large raster, I am going to create tin and visible area.

Is it possible to do these process without clipping?

Re: Troubles in a tool using multiprocessing

DanPatterson_Retired — Fri, 08 Jun 2018 01:15:01 GMT

I imagine using tine to raster, but has the first part worked?

Re: Troubles in a tool using multiprocessing

AzusaIshizaki — Fri, 08 Jun 2018 02:01:38 GMT

No.

First process: clip raster

Second process: raster to tin, raster to visible area

I want to do the whole process (first and second process) in multiprocessing.

Re: Troubles in a tool using multiprocessing

DanPatterson_Retired — Fri, 08 Jun 2018 15:46:58 GMT

I will let others jump in then. I suspect my suggestions haven't been useful