On Wed, Sep 7, 2011 at 2:25 PM, Ross Maidment < r.i.maidm...@pgr.reading.ac.uk> wrote:
> Hi, > > I am using the package ncdf to create netCDF files and I want to mimic the > the header of an exiting netCDF file created outside of R. Below is what the > existing header looks like (part of it that is different): > > netcdf ccd1984_05_08 { > dimensions: > lat = 1974 ; > [...listings omitted...] > I am unable to replicate the variables attributes that exist in the first > example in the second example. Is there anyway to transfer across the header > information or edit the ncdf package to do this? > Hi Ross, to specify the units attribute in the output file, you just set the units parameter correctly when calling dim.def.ncdf. Since your ncdf-created file has blank units attributes, I can only assume your R code is doing something like this: dim_lon <- dim.def.ncdf( 'lon', "", lonvals ) when it should be doing something more like this: dim_lon <- dim.def.ncdf( 'lon', "degrees_east", lonvals ), etc. Easiest way to "copy" a dimension is R code like this: file2copy = 'old_file.nc' ncid_old = open.ncdf( file2copy ) dim2copy = "lon" old_dim = ncid_old$dim[[ dim2copy ]] new_dim = dim.def.ncdf( old_dim$name, old_dim$units, old_dim$vals, unlim=old_dim$unlim, longname=old_dim$longname ) For attributes other than units, you can use the att.put.ncdf() call. You make this call AFTER you have created the output file: ... ncid_out = create.ncdf( 'new_output_file.nc', list(output_vars1,...,output_varN)) att.put.ncdf( ncid_out, 'lat', 'axis', 'Y' ) att.put.ncdf( ncid_out, 'ccd', 'Unit_duration', 7.5 ) etc. --Dave > > ______________________________________________ > 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. > -- 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 [[alternative HTML version deleted]] ______________________________________________ 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.