Hi Roy and David, My main problem is how to interpret the coordinate system. If I try to open it directly in a GIS software that supports necdf format, the location is far away from where it should be (plots rlong,rlat). All I want to do is to get a data.frame with a column for long, another for lat. However I have no clue what lat or what long I should use.
Here is the ncdump: netcdf precip.DMI.HS1 { dimensions: rlat = 84 ; rlon = 90 ; time = 10800 ; time_bnds = 2 ; variables: float lat(rlat, rlon) ; lat:standard_name = "latitude" ; lat:long_name = "latitude" ; lat:units = "degrees_north" ; float lon(rlat, rlon) ; lon:standard_name = "longitude" ; lon:long_name = "longitude" ; lon:units = "degrees_east" ; float precip(time, rlat, rlon) ; precip:units = "kg m-2 day-1" ; precip:standard_name = "precipitation_amount" ; precip:long_name = "Precipitation" ; precip:cell_methods = "time: mean" ; float rlat(rlat) ; rlat:axis = "Y" ; rlat:standard_name = "rotated_latitude" ; rlat:long_name = "rotated latitude" ; rlat:units = "degrees" ; float rlon(rlon) ; rlon:axis = "X" ; rlon:standard_name = "rotated_longitude" ; rlon:long_name = "rotated longitude" ; rlon:units = "degrees" ; float time(time) ; time:axis = "T" ; time:calendar = "360_day" ; time:long_name = "time" ; time:bounds = "time_bnds" ; time:units = "days since 2071-01-01 00:00:00.0" ; float time_bnds(time, time_bnds) ; char rotated_pole ; rotated_pole:grid_mapping_name = "rotated_latitude_longitude" ; rotated_pole:grid_north_pole_latitude = 37.f ; rotated_pole:grid_north_pole_longitude = -153.f ; // global attributes: :Conventions = "CF1.0" ; :source = "HIRHAM" ; :experiment = "HS1" ; :institution = "DMI" ; } On Fri, Jul 29, 2011 at 3:57 PM, David William Pierce <dpie...@ucsd.edu> wrote: > On Fri, Jul 29, 2011 at 7:44 AM, Ana <rrast...@gmail.com> wrote: >> >> Can someone help me out with a "small" problem? >> >> I've started using netcdf files recently, and I want to extract the grid >> id >> and also the coordinates from a HIRHAM netcdf file. >> I know how to extract a slice of dataset both in space and in time and I >> also know the area that this file should cover, however I have no idea >> regarding the reference for both LAT/LON and RLAT/RLON. >> >> I tried already tried is ArcGIS to give the Lambert Conformal Conic >> projection as the spatial reference, by default arcgis gets the rlat and >> rlon for coordinates. however the resulting raster is displaced from were >> it >> should be. >> >> Can someone help me with this? > > Hello, > > I can't tell if you're asking: > > * How to tell what information is in your netcdf file, > > * How to get the data you need out of your netcdf file, > > * How to interpret the data you are getting from the netcdf file. > > Perhaps you could be a bit clearer? > > As a suggestion, try "ncdump -h <filename.nc>" and look to see what > information is in your file. Is it what you expected & need? > > Regards, > > --Dave > > > -- > David W. Pierce > Division of Climate, Atmospheric Science, and Physical Oceanography > Scripps Institution of Oceanography > (858) 534-8276 (voice) / (858) 534-8561 (fax) dpie...@ucsd.edu > > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.