NCL Home> Application examples> File IO || Data files for some examples
Method 1: Direct output of netCDF: no file predefinitionThis method is the simple, but (possibly) inefficient way to write netCDF files from NCL. This approach is appropriate if you don't have a lot of large sized variables to write to the file. For a more efficient method, see method 2.
;===================================================================== ; Assume variables T, PS exist and that they have coordinate variables ; T is four dimensional: T(time,lev,lat,lon) ; PS is three dimensional: PS(time,lat,lon) ; ; Assume that ORO exists. ORO is two dimensional ; but it does not have any coordinate variables ; or attributes associated with it. ; These must then be explicitly assigned. Assume the ; lat/lon coordinate arrays can be taken from variable T. ; Note that the file name does not have to be same as variable name ;===================================================================== system("/bin/rm -f simple.nc") ; remove any pre-existing file ncdf = addfile("simple.nc" ,"c") ; open output netCDF file ; make time and UNLIMITED dimension ; recommended for most applications filedimdef(ncdf,"time",-1,True) ; output variables directly ncdf->T = T ; 4D ncdf->PS = PS ; 3D ORO!0 = "lat" ; assign named dimensions ORO!1 = "lon" ORO&lat = T&lat ; copy lat from T to ORO ORO&lon = T&lon ORO@long_name = "orography" ; assign attributes ORO@units = "m" ncdf->TOPOGRAPHY = OROThere is no need to explicitly copy the coordinate variables or attributes. They are automatically written to the file when the variables are output.