Curvilinear grids and subregions...

[strandwg@xxxxxxxx (Gary Strand)]

I've got some data on the PCM POP grid (see http://www.cgd.ucar.edu/pcm for 
more about it) and the necessary grid information for it.

In what order should I do the following calls to get a subregion (say, the Gulf
Stream) of that grid properly plotted? I've been stumped for a couple days on
this!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
use pop_data.nc
use gridinfo.nc
!
let xmin = -90; let xmax =  10
let ymin =  20; let ymax =  80
let xdel =  10; let ydel =  10
let mid_lon = `xmin+(xmax-xmin)/2`
let mid_lat = `ymin+(ymax-ymin)/2`
!
go mp_lambert_cyl `mid_lon` `mid_lat`
set region/x=`xmin`:`xmax`/y=`ymin`:`ymax`
let mp_lambda = lon[d=gridinfo.nc] * deg2rad
let mp_phi    = lat[d=gridinfo.nc] * deg2rad
set grid `var[d=1],return=grid`
shade var[d=1]*mp_mask, x_page, y_page
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The above doesn't work - the "set region" command uses the i,j of the original
data, which is only "indexical" space, not geographic space.

I'm hoping I just need to rearrange the order of the calls to get it to work
right!

Thanks.
--
/\        Gary Strand (303) 497-1336                                NCAR ML262A
  \_][    www.cgd.ucar.edu/ccr/strandwg                      1850 Table Mesa Dr
      \___strandwg@ucar.edu                       Boulder, Colorado, USA  80305