Hi Bernardo, Yes, feel free to open a feature request issue. You can assign it to yourself if you think you may tackle it afterwards.
Cheers, Vero El lun, 16 ene 2023 a las 19:20, Bernardo Santos via grass-user (< [email protected]>) escribió: > Hi Makus, > > Nice suggestion, I did not know about this function within r.mapcalc (it > is quite hidden!) > I still do not know how to operationalize it, though. > For now, the solution with R worked, but it could be useful to have > something like that in GRASS in the future. > Should I open an issue with a suggestion? > (I do not have time to do it right now) > > Best > Bernardo > Em quarta-feira, 11 de janeiro de 2023 09:39:17 GMT+1, Markus Neteler < > [email protected]> escreveu: > > > Hi Bernardo, > > Not sure if this helps but there is also this function in r.mapcalc: > > https://grass.osgeo.org/grass78/manuals/r.mapcalc.html > > graph(x,x1,y1[x2,y2..]) convert the x to a y based on points > in a graph F > graph2(x,x1[,x2,..],y1[,y2..]) alternative form of graph() > > The graph() function allows users to specify a x-y conversion using > pairs of x,y coordinates. In some situations a transformation from one > value to another is not easily established mathematically, but can be > represented by a 2-D graph and then linearly interpolated. The graph() > function provides the opportunity to accomplish this. An x-axis value > is provided to the graph function along with the associated graph > represented by a series of x,y pairs. The x values must be > monotonically increasing (each larger than or equal to the previous). > The graph function linearly interpolates between pairs. Any x value > lower the lowest x value (i.e. first) will have the associated y value > returned. Any x value higher than the last will similarly have the > associated y value returned. > [...] > > Perhaps a dynamic (set of) graphs could be constructed? > > Best, > Markus > > On Wed, Dec 14, 2022 at 2:37 PM Bernardo Santos via grass-user > <[email protected]> wrote: > > > > Hi, > > > > I am trying to produce scenarios of past land cover, before hydropower > reservoirs were built. To do so, I need to fill empty pixels from a raster > in the locations where the reservoirs are currently present, using as input > the actual land cover map. I tried doing that with r.neighbors (taking > method=mode) with neighborhoods of increasing size, to replace null pixels > with the most common land cover class in the neighborhood. I also tried > that with r.fill.stats which is basically the same thing. > > However, the results gets very homogeneous, since the interpolated null > cells always get the value of the most common land cover class. > > > > Do anyway know of a method in GRASS to perform a "probabilistic" > neirighborhood analysis, where cells in a neighborhood are given weights > (possibly related to the distance to the central cell and to their > frequency) and these weights are used to stocastically sample a value to > fill the central cell? > > If not in GRASS, does anyway know of such a method in a different > platform, i.e. R? > > > > Thanks! > > Best > > Bernardo > > _______________________________________________ > > grass-user mailing list > > [email protected] > > https://lists.osgeo.org/mailman/listinfo/grass-user > > > > -- > Markus Neteler, PhD > https://www.mundialis.de - free data with free software > https://grass.osgeo.org > https://courses.neteler.org/blog > _______________________________________________ > grass-user mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/grass-user >
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