Re: [R-sig-Geo] formula understanding
Am 24.02.2011 23:19, schrieb Edzer Pebesma: On 02/24/2011 09:40 PM, Anna Gretschel wrote: Dear List, The following formula is given for a spherical model in variofit (geoR). /rho(h) = 1 - 1.5 * (h/phi) + 0.5(h/phi)^3 if h< phi , 0 otherwise /Could anyone explain what the term "if hphi? rho(h) And shouldn't there be a * between 0.5 and (h/phi)? That would have been consistent, but as this is documentatation, I don't think it is wrong. Thanks in advance, Anna [[alternative HTML version deleted]] ___ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo Thank you! If you don't mind I would like to ask you another question: I want to use this function to calculate a rmse (root mean square error) for my fitted models. obs beeing the observed data (in my case variog$v) and pred beeing the predicted data I use the following formula: rmse <- function(obs, pred) sqrt(mean((obs-pred)^2)) pred I calculated like this: pre<- 1 - 1.5 * (h/phi) + 0.5(h/phi)^3 if h< phi , 0 otherwise with phi beeing the range and h beeing the distances (variog$u) The output however is not reliable so I think I made a mistake but cannot figure out what is wrong. Do you have an idea what I where the error is in reasoning? Thank you so much for allways replying to my beginners questions :) Anna ___ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo
Re: [R-sig-Geo] formula understanding
On 02/24/2011 09:40 PM, Anna Gretschel wrote: > Dear List, > > The following formula is given for a spherical model in variofit (geoR). > > /rho(h) = 1 - 1.5 * (h/phi) + 0.5(h/phi)^3 if h < phi , 0 otherwise > > /Could anyone explain what the term "if h part of the equation becomes 0 if h>phi? rho(h) > And shouldn't there be a * between 0.5 and (h/phi)? That would have been consistent, but as this is documentatation, I don't think it is wrong. > Thanks in advance, > Anna > > [[alternative HTML version deleted]] > > ___ > R-sig-Geo mailing list > R-sig-Geo@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of Münster Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de http://www.52north.org/geostatistics e.pebe...@wwu.de ___ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo
