20000228: PTCON level

>From: Bill Fingerhut <address@hidden>
>Organization: Lyndon State College
>Keywords: 200002281422.HAA00315 McIDAS PTCON

Bill,

>I tried to compute dewpoint depression and save the grid for later
>use. If I contour data from grid 1 it looks okay. The problem is
>that the LEVEL is missing. This creates a problem when I go one
>step further, and pass several grids to XSECTG. 
>
>According to the help for PTCON, the level is supposed to default
>to that in the SEL= clause?

The snippit from the online McIDAS-X User's Guide on PTCON seems to indicate
that one can specify the level of the computed parameter with the GINFO=
keyword:

GINFO= 
        level lunit day time src fhour
        values to assign to the header of the computed parameter grid
        created with the PARAM and Pn keywords, where:
  
         
         level 
              grid level
  
         lunit 
              grid level units; 2 character maximum
  
         day 
              grid day (default=value specified for DAY in the SELECT
              keyword; otherwise, default=today)
         
         time 
              grid time (default=value specified for TIME in the SELECT
              keyword; otherwise, default=22:22:22)
         
         src 
              grid source (default=MDX)
         
         fhour 
              grid forecast hour (default=0)


The other keyword that may be relevant is the GLEV= one:

GLEV= 
         level unit 
                grid level to use in the grid header and on the display
                (default=value entered for LEV, THA, or P in the SELECT
                keyword clause ; otherwise, no default)

>PTCON RTPTSRC/UPPERMAND OUT=SAVE MYDATA/GRIDS.1 MAP=NA PRO=CONF LLI=3.1 3.1 SE
> L='DAY 2000059;
>TIME 12;P 1000' PAR='DD=P1-P2' P1=T P2=TD              
>Number of data points input to objective analysis:  165                       
>PTCON:  Done                                                                  
>                                                         
>IGG LIST GRIDF=2001                                                           
> Grid file:  2001 **                                **                        
>    #  YYDDD HHMMSS NAME  LEVEL  SRC   VT  NR  NC   LLNW    ROWINC  COLINC    
> ----- ----- ------ ---- ------- ----  --  --  -- --------  ------  ------    
>     1 99941 120000 DD           MDX    0  31 117  90/ 180  3.1000  3.1000    
>  ---End of Listing       

Hmm...  You told PTCON to save the calculated grid in the first position of
the MYDATA/GRIDS dataset.  If your MYDATA is defined like the default we
send out, then the GRID file written to would be 1 (GRID0001), not 2001.

The other thing that is odd about your IGG listing is the DAY.  It is likely,
however, that the strange looking day, 99941, is a reflection of the
non-Y2K capability of IGG.  GRDLIST should be used instead of IGG whenever
possible.

Please let me know if:

o you were looking at the wrong GRID file for IGG output
o the GINFO and/or GLEV keywords do what you want

Tom

>From address@hidden  Mon Feb 28 12:05:42 2000

Tom,

Output was going to gridfile 2001.

I had tried GLEV= before, and that did not help.
Just now, I tried GIN=      , and that did the trick.
I'll use this, but it seems a little redundant?

Thanks, Bill

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
< Bill Fingerhut, Professor              PHONE: 802-626-6257 >
< Meteorology Dept                       FAX:   802-626-9770 >
< Lyndon State College                                       >
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