*.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.pog...@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@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/grass-user -- Dott. Gianluca Massei, PhD
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