Questions tagged [parallel-processing]

Use this tag when asking questions about multi or parallel processing - a programming paradigm used to speed up computationally intensive geoprocessing tasks by executing them over multiple CPU cores or threads.

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Batch intersect and multiprocessing with arcpy

I admit what I am working on is way over my head, especially as I've only been dabbling in python for a few months. I am attempting to write a script that allows me to use Intersect analysis on about ...
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1answer
3k views

Using 'sp' method to subset SpatialPointsDataFrame with SpatialPolygon returns error in parLapply()

I have numerous very large data sets of ship tracking data (Automated Information System; AIS). These are originally in a file geodatabase and can be downloaded here (this is a smaller file for ...
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2answers
3k views

Methods for optimizing multcore processing in ArcGIS

I am interested in learning methods to utilize the full extent of multicore processing power available on a desktop computer. Arc states that background geoprocessing allows the user to utilize ...
2
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0answers
68 views

Avoiding edges using GRASS generalization?

I'm trying to process the national wide land cover data into vector polygons. In order to be quick I separate the data into several tiles and process them in parallel. process flow is : 1. v.in.ogr ...
4
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1answer
311 views

Splitting data into geographic zones for multiprocessing

I have been looking at multiprocessing and tools like Find Duplicates in Big Data and they seem to simply split the data into sections based on rows/number of records. I am trying to do an intersect ...
3
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1answer
717 views

How to use multiprocessing or pool to boost up the performance of ArcPy script

I created some arcpy script which actually runs slow on huge dataset. such as 100000 feature in it. I read from below path that multiprocessing can boost up arcpy script script performance. http://...
3
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0answers
348 views

Multiprocessing in python qgis?

When i try to do mutliprocessing in python Qgis it doesn't work from multiprocessing import Process,Lock import multiprocessing def name1(l,i): print i if __name__=='__main__': lock=Lock() ...
3
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2answers
695 views

Python and QGIS multiprocessing documentation?

Where can we find better documention for python QGIS multiprocessing. Especially regarding the multiprocessing of python and QGIS.
2
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1answer
998 views

Multiprocessing error in QGIS with Python on Windows?

I have this error when I try to use Manager() from python multiprocessing library. (Just start QGIS open Python console and execute the two following lines) >>> import multiprocessing >&...
2
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1answer
338 views

problem deleting shapefiles because still in use by arcpy cursor [duplicate]

I have a function outputTblContents which contains def outputTblContents ( path ): rows = arcpy.SearchCursor(path, fields="alpha; beta") for row in rows: print("{0} => {1}").format(...
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1answer
2k views

How to write to a single table via Python multiprocessing

A comment in the post Can multiprocessing with arcpy be run in a script tool? got me thinking, as I often need to do exactly this: Just beware of deadlocking situations (two Insert cursors in the ...
4
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0answers
301 views

How to use the multiprocessing module on python to execute a spatial join? [closed]

I have several shapefiles of the entire Amazon rainforest each with millions of polygons (they are fairly detailed and take some time to draw on ArcMap). I need each of these shapefiles to be ...
2
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1answer
361 views

Setting ArcPy environment variables with Python multiprocessing?

I have a script which uses ArcPy + Python multiprocessing. Are ArcPy environment variables shared between separate Python processes? If I write to arcpy.env.extent from within each process am I ...
5
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1answer
926 views

How to implement multiprocessing with multiple geoprocesses?

I am relatively new to Python and thought I would give a stab at multiprocessing. I have a script that runs well in IDLE or as an ArcMap toolbox script. After perusing these forums and docs.python, I ...
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1answer
3k views

How to write output from subprocess to disk (using multiprocessing)

This code was developed from another question I posted about how to kill an arcpy tool if it takes longer than a specified time. See How to cancel tool execution in python. Using the multiprocssing ...
3
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1answer
798 views

arcpy with multiprocessing throws “UnpickleableError: Cannot pickle <type 'geoprocessing Layer object'> objects”

I'm attempting to speed up a process which is currently running synchronously, by using the python multiprocessing module. I'm having trouble sending a feature layer to a function which is called by ...
4
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1answer
5k views

Python Postgres Multiprocessing speed increase

I'm trying to speed up my PostGIS queries using multiprocessing. My current setup is using python and psycopg2 such as below. Although this has given a speed increase, it still seems like there are ...
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1answer
188 views

Maintaining reference to feature layer (rather than its name string) throughout Python script? [duplicate]

When creating a Layer in arcpy, the syntax uses a string to denote the layer name, as shown in the Make Feature Layer sample script: import arcpy arcpy.env.workspace = "C:\Program Files (x86)\ArcGIS\...
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0answers
39 views

Sending commands into FGDB

I have a large .gdb of all blocks in the United States, available from Census. I would like to create a point shape file of all census tract centroids in the US. I have QGIS with FileGDB enabled, as ...
20
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1answer
2k views

ArcGIS 10.1 Python AddIn Using Multiprocessing crashes ArcMap?

I would like to run a multiprocessing task from a python add-in tool. My issue is that the process keeps failing. Basically crashes ArcMap. Here is my basic code: def function(startOID, endOID, fc)...
22
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2answers
3k views

Arcpy Parallel Processing Environment

I recently discovered the Parallel Processing environment setting in ArcGIS (this must be new to 10.1), however, there is no mention as to what tools are designed to utilize this environment setting. ...
6
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1answer
1k views

How to do parallel queries in postgis [closed]

Is there any way to do queries in postgis using multiple cores in a transparent way, other than splitting my queries among several client connections ?
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1answer
1k views

Can I increase the number of processes in ArcGis Server 10.1?

I use ArcMap 10.1. I have a map with many Mosaic and Raster layers. They are stored in many gdb-s. I publish this map with option "Create tiles on demand". But this tiles are created very slowly (may ...
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2answers
4k views

Execute multiple process in parallel of Arcpy script

I have seen some difficult ways to do parallel processing, but I wonder if it is possible to simply execute multiple process of the same ArcPy script at the same time. My script makes some changes to ...
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2answers
833 views

Parallel Computing and Raster Operations in ArcObjects gives cryptic error

This is a problem I have been struggling with for awhile. The code below takes 1-3 input feature layers (pFLayer) that were stored into a list called pFeatureLayerCollection, casts them into ...
6
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1answer
417 views

parallelization of raster mosaic

I would like to create a raster mosaic of the national USGS NED 30m DEM (~50 GB). I'd like to leverage parallel processing using python multiprocessing module where possible. I'm using ArcGIS 10.0. My ...
12
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1answer
2k views

OGR/GDAL threading results in low core utilization

I'm trying to process some raster data using ogr/gdal and I can't seem to get full utilization of all the cores on my machine. When I only run the process on a single core, I get 100% utilization of ...