[Qgis-user] point sampling tool is there anyway to speed it up and keep it going

[Anita Graser]

Would it be an option for you to rasterize the polygons and then sample  
the raster? That's always much faster.

Best wishes,
Anita

Am 10.01.2014, 21:39 Uhr, schrieb Michael.Dodd <Michael.Dodd at open.ac.uk>:

> Thanks for the suggestion, I tried it a couple of times but after  
> 1000-2000 points it crashed (different number of points each time I  
> tried).  It was very quick doing this in a few seconds whereas point  
> sampling had taken several minutes for this number, however point  
> sampling went on for hours until it crashed with about 230,000 done of  
> the 300,000 total points.
> ________________________________________
> From: Anita Graser [anitagraser at gmx.at]
> Sent: Friday, January 10, 2014 7:44 PM
> To: qgis-user at lists.osgeo.org; Michael.Dodd
> Subject: Re: [Qgis-user] point sampling tool is there anyway to speed it  
> up and keep it going
>
> Hi Michael,
>
> Try the SAGA implementation (through Processing). It's much faster, as
> described in
> http://anitagraser.com/2013/10/02/add-polygon-attributes-to-points-vs-join-attributes-by-location/
>
> Best wishes,
> Anita
>
>
> Am 10.01.2014, 19:41 Uhr, schrieb Michael.Dodd <Michael.Dodd at open.ac.uk>:
>
>> The point sampling plugin can be very effective but is slow when dealing
>> with a large number of points and a complex area to be sampled e.g.
>> hundreds of thousands of points on a relatively detailed map of world
>> countries.  I can cope with it being slow by just accepting it will take
>> all day to run BUT it never completes because there is always something
>> that happens on the pc that stops it, the last time it happened after
>> about 4 hours with a couple more hours to run.  If you try to use any
>> other program on the pc then the tool stops and also freezes qgis.  am
>> currently running qgis 2.0.1 on windows7 64bit with quite a lot of ram
>> although i note it never uses more than about 13% of the total ram.  I
>> used to run the tool with earlier versions of qgis on windowsXP and had
>> the same issue with it stopping if any other program was opened on the
>> pc.
>> -- The Open University is incorporated by Royal Charter (RC 000391), an
>> exempt charity in England & Wales and a charity registered in Scotland
>> (SC 038302).
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>
>
> --
> anitagraser.com
> -- The Open University is incorporated by Royal Charter (RC 000391), an  
> exempt charity in England & Wales and a charity registered in Scotland  
> (SC 038302).


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