incompatible grids

[Ted Pollock]

Hi all,

I have two global grids of different resolutions and I'd like to
compare them but I'm having problems since the two sets of grid points
do not line up. (I get an incompatible grid error if I try to take the
difference between the two.) The higher resolution grid is netcdf
format and the other is not.

I thought the easiest way to do this would be to use the pdef entry
and its interpolations to map the non-netcdf grid onto the higher
resolution netcdf grid. Unfortunately I'm not sure how to get pdef to
work with the mercator projection.

I'm also open to mapping the netcdf grid onto the lower resolution
grid using a ctl file if thats possible but I think that might also
require a pdef entry. (I'm still using gradsv1.9b4.)

Any help on this would be much appreciated. (Below I've included parts
of the ctl file and ncdump from the two datasets.)

Thanks in advance
-Ted

CTL FILE:

XDEF 96 LINEAR  0.0   3.75
*
YDEF 80 GAUSR30 1
*

NCDUMP:
dimensions:
          lon = 192 ;
          lat = 94 ;
          time = UNLIMITED ; // (722 currently)

variables:
          float lat(lat) ;
                  lat:units = "degrees_north" ;
                  lat:actual_range = 88.542f, -88.542f ;
                  lat:long_name = "Latitude" ;
          float lon(lon) ;
                  lon:units = "degrees_east" ;
                  lon:long_name = "Longitude" ;
                  lon:actual_range = 0.f, 358.125f ;
          double time(time) ;