Re: NARR contour plots

From: Mary Haley <haley_at_nyahnyahspammersnyahnyah>
Date: Wed, 18 Mar 2009 09:36:44 -0600

Hi Dave,

See example 13 at:

This isn't NARR data, but it shows how to overlay contours and vectors
on a map.

For NARR data, since you have 2D lat/lon, this example would
additionally need the special "lon2d" and "lat2d" attributes attached to
the data, OR, you would need to know the exact map projection that
your data is on, and set the special "tfDoNDCOverlay" resource
to True. See the NARR examples for how to use this special resource:

Meanwhile, if you don't have the exact map projection, and you want to
use the 2D lat/lon coords: assumed that the data in the panel 13
example had 2D lat/lon coordinates called "lat" and "lon" on the file.
Then, we would do something like this:

   a = addfile("","r")
   u = a->U(1,:,:)
   v = a->V(1,:,:)
   speed = sqrt(u^2+v^2)
   u_at_lat2d = a->lat
    u_at_lon2d = a->lon
   v_at_lat2d = u_at_lat2d
   v_at_lon2d = u_at_lon2d
   speed_at_lat2d = u_at_lat2d
   speed_at_lon2d = u_at_lon2d
Everything else would be the same.
For the vector plot, if you want wind barbs, set:
vcres_at_vcGlpyhStyle = "WindBarb"

On Mar 17, 2009, at 8:45 PM, David Small wrote:

> Hello everyone,
> The NARR dataset uses 2 dimensional latitude and longitude. Is it
> possible to lay several sets of contours over top of one another,
> possibly with vector winds? If so, can someone tell me how to do
> it?
> Thank you very much.
> Dave
> --
> David Small
> Graduate Research Assistant
> Department of Atmospheric and Oceanic Sciences
> McGill University
> Montreal, Quebec, Canada
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Received on Wed Mar 18 2009 - 09:36:44 MDT

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