Arnaud Dowkiw
2005-Nov-09 16:20 UTC
[R] Replace missing values in spatial design using moving average
Dera R helpers, I have a (x,y,z) data file where x and y are spatial coordinates and z a variable. I have some missing values in the z column and I would like to replace them with an optimized estimation from the neighbour cells. I could not find any function in R to do that. Is anybody aware of such function ? Maybe someone knows how to implement the Papadakis method in R... Thanks for your help, Arnaud DOWKIW - - - - - - - - - - - - - - - - - - - - - - - Arnaud DOWKIW INRA Unit?? Am??lioration G??n??tique et Physiologie Foresti??res 2163 avenue de la Pomme de Pin BP 20619 ARDON 45166 OLIVET CEDEX FRANCE Tel. + 33 2 38 41 78 00 Fax. + 33 2 38 41 48 09 - - - - - - - - - - - - - - - - - - - - - - -
Roger Bivand
2005-Nov-16 12:00 UTC
[R] Replace missing values in spatial design using moving average
On Wed, 9 Nov 2005, Arnaud Dowkiw wrote:> Dera R helpers, > > I have a (x,y,z) data file where x and y are spatial coordinates and z a > variable. I have some missing values in the z column and I would like to > replace them with an optimized estimation from the neighbour cells. I could > not find any function in R to do that. Is anybody aware of such function ? > Maybe someone knows how to implement the Papadakis method in R... > Thanks for your help,I'm not sure about the Papadakis method, I don't think it is there, though could be implemented using standard tools. Ripley (1981) relates the method to SAR and CAR models, but predicting with them is far from easy (there are papers by Martin from the 1980's about this). Are geostatistical methods an option for you? That is, what is the support of your cells?> > Arnaud DOWKIW > > - - - - - - - - - - - - - - - - - - - - - - - > Arnaud DOWKIW > INRA > Unit?? Am??lioration G??n??tique et Physiologie Foresti??res > 2163 avenue de la Pomme de Pin > BP 20619 ARDON > 45166 OLIVET CEDEX > FRANCE > Tel. + 33 2 38 41 78 00 > Fax. + 33 2 38 41 48 09 > - - - - - - - - - - - - - - - - - - - - - - - > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html >-- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand at nhh.no