Dear the R-sig-geo users, I have been trying to interpolate rainfall and temperature data for 8 stations and that needs to be interpolated at a farm level so that I have farm level temperature and rainfall observations. I am trying to use R for that. First off is kriging in gstat something that I can use for that purpose? I have latitude and longitude information. Can somebody give me some tips on how I can go about that? many thanks in advance minti
gstat for interpolation
3 messages · Ashton Shortridge, Mintewab Bezabih
Dear Minti, with only 8 stations there is not enough data to construct reliable covariance (variogram) models. Eight stations simply isn't very many for reliably modeling spatial structure. You would be much better off just using inverse distance weighting (IDW), which gstat can also do, or even nearest-neighbor interpolation. Second, it would be best to project the latitudes and longitudes to a planar coordinate system appropriate for your study region. I think gstat may be able to deal with spherical distances, but I haven't any experience with that. The rgdal package is one of several that can do this in R; it can also be done in GIS or with other geospatial tools. Yours, Ashton
On 09/07/12, Mintewab Bezabih, wrote:
Dear the R-sig-geo users, I have been trying to interpolate rainfall and temperature data for 8 stations and that needs to be interpolated at a farm level so that I have farm level temperature and rainfall observations. I am trying to use R for that. First off is kriging in gstat something that I can use for that purpose? I have latitude and longitude information. Can somebody give me some tips on how I can go about that? many thanks in advance minti
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----- Ashton Shortridge Associate Professor ashton at msu.edu Dept of Geography http://www.msu.edu/~ashton 235 Geography Building ph (517) 432-3561 Michigan State University fx (517) 432-1671
4 days later
Dear Ashton, I am fine with using the Inverse Distance Weighting or the Nearest Neighbour and I can also use your suggestion of the two coordinate plotting. The purpose of my exercise is to get interpolated figures that I will use in further statistical analysis (I am an economist and my understanding of GIS issues is very limited). I would be delighted if you could give me more tips on how I could go about this. I had previously attempted doing interpolation with R (which is perhaps totally wrong but I can post it here if you think I can incorporate your suggestions on there Many thanks. Regards, Minti
On Fri, Sep 7, 2012 at 2:45 PM, Ashton Shortridge <ashton at msu.edu> wrote:
Dear Minti, with only 8 stations there is not enough data to construct reliable covariance (variogram) models. Eight stations simply isn't very many for reliably modeling spatial structure. You would be much better off just using inverse distance weighting (IDW), which gstat can also do, or even nearest-neighbor interpolation. Second, it would be best to project the latitudes and longitudes to a planar coordinate system appropriate for your study region. I think gstat may be able to deal with spherical distances, but I haven't any experience with that. The rgdal package is one of several that can do this in R; it can also be done in GIS or with other geospatial tools. Yours, Ashton On 09/07/12, Mintewab Bezabih, wrote:
Dear the R-sig-geo users, I have been trying to interpolate rainfall and temperature data for 8 stations and that needs to be interpolated at a farm level so that I have farm level temperature and rainfall observations. I am trying to use R for that. First off is kriging in gstat something that I can use for that purpose? I have latitude and longitude information. Can somebody give me some tips on how I can go about that? many thanks in advance minti
_______________________________________________ R-sig-Geo mailing list R-sig-Geo at r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo
----- Ashton Shortridge Associate Professor ashton at msu.edu Dept of Geography http://www.msu.edu/~ashton 235 Geography Building ph (517) 432-3561 Michigan State University fx (517) 432-1671