Re: how to use Pressure/Height vs. Latitude/Longitude

Echo,

I assume you are talking about using the gsn_csm_pres_hgt plotting
function?

If so, the main requirements are:

  - The input data must be 2D and the leftmost dimension must
represent pressure, the rightmost dimension latitude or longitude
(although I think the function will work if the rightmost dimension
is something else).

  - The leftmost dimension of the input data must have a coordinate
array attached, with units of pascals, hecto-pascals, or millibars.
The routine will look for a "units" attribute attached to your
coordinate array to verify this.

If you are running into problems because your pressure coordinate
array doesn't have a "units", then you can attach one yourself.

For example, if the data variable is called "u", and your level
dimension is called "lev", then you can do this:

    u&lev@units = "mb" ; if millibars
    u&lev@units = "pa" ; if pascals

If you are not sure about your data, do a "printVarSummary" on it:

   printVarSummary(u)

If you see that "u" contains a coordinate array, then you can also do
a printVarSummary on it, to see what the units are:

   printVarSummary(u&lev) ; just an example, you'll need to enter
the correct level dimension name

--Mary

On Nov 4, 2009, at 1:54 AM, yjxstsp2 wrote:

> Dear all,
> I met problems when I used Pressure/Height vs. Latitude. The
> nc files were converted by MCIP3.0. I want to know if there are
> special requirements about the nc file dimentions or the draw
> variables?
> Best wishes
> Echo
>
>
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Received on Wed Nov 4 12:39:20 2009