[GRASS-dev] [GRASS GIS] #1874: latitudinal bias in sample points created with r.random

[Paulo van Breugel]

Not only in theory, I actually use it all the time :-). And you can 
achieve the same by setting all the areas outside your target area to 
NULL. I like how the combination of the two gives you a fine control 
over how you want to sample an area. You can even do the same with the 
cover layer. Although to be honest,  I don't really see the added value 
of having this option to define a cover layer, but that is another point.

By the way, it seems the issue of under-sampling was solved too? At 
least, in the limited trials I did, when generating random points I am 
actually getting the requested number of sample points, which I didn't 
previously! Super!!

Cheers,

Paulo





On 02/07/2013 09:39 AM, Markus Metz wrote:
> On Thu, Feb 7, 2013 at 8:34 AM, Paulo van Breugel
> <p.vanbreugel at gmail.com> wrote:
>> Thanks pointing it out. I have actually used the script some time ago. I
>> think I found that it becomes a bit slow when working with large number of
>> points, but I am going to try in grass 7, see if it is any faster due to
>> faster vector handling.
>>
> In theory, r.random should work for irregular areas if you set a MASK.
>
> Markus M
>
>> Cheers,
>>
>> Paulo
>>
>>
>> On Thu, Feb 7, 2013 at 2:44 AM, GRASS GIS <trac at osgeo.org> wrote:
>>> #1874: latitudinal bias in sample points created with r.random
>>>
>>> ------------------------+---------------------------------------------------
>>>   Reporter:  pvanbosgeo  |       Owner:  grass-dev@…
>>>       Type:  defect      |      Status:  new
>>>   Priority:  major       |   Milestone:  7.0.0
>>> Component:  Raster      |     Version:  svn-trunk
>>>   Keywords:  r.random    |    Platform:  Linux
>>>        Cpu:  x86-64      |
>>>
>>> ------------------------+---------------------------------------------------
>>>
>>> Comment(by hamish):
>>>
>>>   > It's internal
>>>
>>>   (a friend was terrible with apostrophes and to/too/two & after too many
>>>   emails it begins to look natural and the bad habit has rubbed off on me!
>>>   argh!)
>>>
>>> --
>>> Ticket URL: <https://trac.osgeo.org/grass/ticket/1874#comment:6>
>>> GRASS GIS <http://grass.osgeo.org>
>>>
>>
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