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[GEMPAK #LHX-868270]: GEMPAK - obtaining coordinates of contours

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  • Subject: [GEMPAK #LHX-868270]: GEMPAK - obtaining coordinates of contours
  • Date: Mon, 09 Jul 2007 09:56:45 -0600
> Institution: Weathernews
> Package Version: 5.10.2
> Operating System: Linux
> Hardware Information: P4 processor, 256MB RAM, 40GB HD
> Inquiry: Hello,
> 
> I have a mapping program which I'd like to overlay bounded areas with certain 
> weather descriptions, for example a bounded/shaded area with a "windy" area, 
> or areas of precipitation, etc.  Can you tell me if GEMPAK is capable of 
> either outputting the coordinates to a bounded region containing, for example 
> surface wind speeds above a given threshold, or if it's possible to send the 
> coordinates of contours such as those created in gdcntr to a text file?  I've 
> so far been unable to find anything addressing this issue online.
> 
> Thanks!
> Jon Oxtoby
> 
> 

Jon,

I'm assuming that your mapping program is external to GEMPAK. If you wanted to 
craete boundaries
for use within GEMPAK programs for overlays, there are several possibilities.

To obtain the coordinates of a contour for use outside of GEMPAK you can
use GDPLOT2 to contour your data. Set the LINE info to "-1" so that each contour
is drawn without breaking the line for line labels such as:
LINE = 5/1/1/-1

Use the VG device driver to output your data to a vector graphics file.

You can use the programs vgftoascii to dump out the contents of
your vgf file to ascii information so that you can obtain the lat/lon values
of the contour boundaries for your other program.

Note that if you were using the VGF within GEMPAK, you could import it into
NMAP2's product generation and edit/modify the contours and labels
(you can still do that to clean up a set of contours/bounds).

Also of note is that since 5.10.1, you can add a text string in CINT as a label
for a given value so that your could annotate a contour with the string,
eg label the 0C contour as "Freezing" or a 15 m/s isotach as "Windy".

The GPMAP program allows you to add BND types to annotate maps with symbold 
according to boundaries etc. A vgf file can be converted into a bounds file for 
GEMPAK as well through vgftobnd.

Steve Chiswell
Unidata User Support

> 
> 


Ticket Details
===================
Ticket ID: LHX-868270
Department: Support GEMPAK
Priority: Normal
Status: Closed