[GRASS-user] Question to the input seed grid of i.segment

[Paulo van Breugel]

On 28-02-17 14:35, Moritz Lennert wrote:
> Le Fri, 10 Feb 2017 19:15:25 +0100,
> Paulo van Breugel <p.vanbreugel at gmail.com> a écrit :
>
>> On 10-02-17 18:41, Moritz Lennert wrote:
>>   [...]
>>   [...]
>>   [...]
>>   [...]
>>   [...]
>>   [...]
>>   [...]
>>   [...]
>>   [...]
>>>> Besides, manually, I calculated
>>>> Moran's I and Intrasegment Variance by i.segment with 8 instead of
>>>> 4 neighbors (default). Even if the object looks kind of "
>>>> pixelated" at the border, I received smaller Moran's I and
>>>> Intrasegment Variance values with i.segment 8 NB in comparison to
>>>> 4 NB (same settings for minsize and threshold). Maybe the "-d"
>>>> flag of i.segment could also be added to i.segment.uspo...
>>> That shouldn't be too difficult. Internally, i.segment.uspo uses
>>> the addon r.neighborhoodmatrix which has a '-d' flag. I just really
>>> do not have the time to implement this right now. You could try
>>> yourself by opening the i.segment.uspo (or on Windows
>>> i.segment.uspo.py) file and adding "flags='d'" to the call to
>>> r.neighborhoodmatrix (lines 535 and following):
>>>
>>>      res = gscript.read_command('r.neighborhoodmatrix',
>>>                                 input_=mapname,
>>>                                 output='-',
>>>                                 sep='comma',
>>>                     flags='d',
>>>                                 quiet=True)
>>>
>>>
>>> This will always apply the flag. When I have time I can add this as
>>> a flag to i.segment.uspo.
>>>
>>> A slightly larger project I have is to actually extract the code
>>> for the calculation of the spatial autocorrelation and create a
>>> "r.spatialautocorrelation" module. But not now... ;-)
>> +1 (or make that a double plus) that would be really great!
>
> r70696: r.object.spatialautocor: new addon to calculate global spatial
> autocorrelation for raster objects
Brilliant, will try it out a.sa.p.
>
> Moritz