Re: tripolar data and mp_stereographic_north

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi Xingren,
This turns out to be pretty simple.  Run the map projection script, in 
this case mp_stereographic_north.jnl, to define the map projection 
variables, and then substitute the curvilinear coordinates from your 
dataset for the coordinates used in the script. (In rectangular 
coordinates, the script just uses X and Y from the variable.)

  ! dataset includes curvilinear coordinates like geolon_vert_t, 
geolat_vert_t,
  ! and variables, for instance wet, a land/sea flag.
 
  yes? use tripolar_data.nc
 
  yes? go mp_stereographic_north.jnl
  yes? set region/y=60:90N
  yes? set grid geolon_vert_t    ! one of the curvilinear variables in 
your file
  yes? go mp_aspect
 
  ! Reset the coordinates to use the curvilinear coordinates from the 
tri-polar
  ! grid, in radians. The shade command can use coordinate variables 
that define
  ! the edges of the grid cells.
 
  yes? let mp_lambda = geolon_vert_t* deg2rad
  yes? let mp_phi = geolat_vert_t* deg2rad
 
  yes? shade/noaxes/lev=(0,2,1) wet, x_page, y_page
 
  ! Here is a way to show the grid points used in a plot
 
  yes? plot/vs/over/nolab/sym=3/siz=0.03  x_page, y_page
 
Ansley

Xingren Wu wrote:

> Hi,
>
> I need to plot tripolar data (shade var,geolon,geolat) on a 
> stereographic projection.
> Can anyone help?
>
> Thanks,
> Xingren Wu