On Sat, Feb 21, 2015 at 2:08 PM, Nikos Alexandris <[email protected]> wrote: > Hi devs, > > and advanced users. Has anyone perforned, or has plans to implement, > non-linear (multi-) regression in GRASS (not through R, of course)?
If it is raster based, you can use r.regression.multi to perform non-linear (multi-) regression in GRASS. It depends on what you mean with non-linear. E.g. if you want to perform a second-order multiple regression with 2 predictors, the formula is in R syntax y ~ x1 + x2 + x1 * x2 + x1 * x1 + x2 * x2 You can calculate the terms x1 * x2, x1 * x1, x2 * x2 with r.mapcalc and feed everything to r.regression.multi. logarithmic: y ~ log(x1) r.mapcalc "logx1 = log(x1)" exponential: y ~ exp(x1) r.mapcalc "expx1 = exp(x1)" A combination of say a 4th-order polynomial with exponential components and 10 predictors could be constructed accordingly. HTH, Markus M > > Thank you, Nikos > _______________________________________________ > grass-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-dev _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
