[GRASS-user] r.soils.texture question

[Gianluca Massei]

yes, of course!
GM

Il giorno gio 25 giu 2020 alle ore 09:51 Laura Poggio <
laura.poggio at gmail.com> ha scritto:

> Hi Gianluca,
> thanks for the explanation. It was very useful. Thanks to your
> explanations I managed to modify the DAT file to reproduce the USDA-NRCS
> texture triangle
> <https://www.nrcs.usda.gov/Internet/FSE_MEDIA/nrcs142p2_050619.jpg>. We
> are doing some final checks. After that, if you are interested, I can share
> the DAT file.
>
> Thanks a lot!
> Laura
>
> On Fri, 12 Jun 2020 at 22:27, Gianluca Massei <
> agr.gianluca.massei at gmail.com> wrote:
>
>> *.dat files are derived from  TALCPP (
>> https://www.tandfonline.com/doi/abs/10.1081/CSS-120017410). The values
>> describe polygons coordinates for different class inside the texture
>> triangle. In r.soils.texture is implemented an algorithm to check if a
>> single point is inside or outside a texture polygon. If the point is
>> inside it is labeled with the correspondent texture code and used to build
>> a texture map.
>> By
>>
>> Il giorno ven 12 giu 2020 alle ore 08:10 Laura Poggio <
>> laura.poggio at gmail.com> ha scritto:
>>
>>> Dear all,
>>> I am looking at the DAT file
>>> <https://svn.osgeo.org/grass/grass-addons/grass7/raster/r.soils.texture/scheme/USDA.dat>
>>> for USDA soil texture classification for the r.soil.texture addon.
>>> I have a couple of questions.
>>>
>>> 1) the class silt-loam appears twice (number 8 and 12). Is this
>>> intentional and needed for the calculations?
>>>
>>> 2) Could you please explain the structure of the DAT file? As example
>>> 1
>>> 6
>>> 0 0 20 45 45 0
>>> 100 60 40 40 55 100
>>>
>>> First line: I think is the class value as written in the pixel.
>>> Second line: not sure
>>> Following two lines: I think they are somehow the limits of sand, silt
>>> and clay. However I can not really understand in which order.
>>>
>>> Thank you very much in advance
>>> Laura
>>>
>>> _______________________________________________
>>> grass-user mailing list
>>> grass-user at lists.osgeo.org
>>> https://lists.osgeo.org/mailman/listinfo/grass-user
>>
>>
>>
>> --
>> Dott. Gianluca Massei, PhD
>>
>

-- 
Dott. Gianluca Massei, PhD
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