20010425: Gempak- Consistent Colors

Mike,

You can use gdplot2 to save on running gdcntr multiple times.

One solution is to split the color bar into >= 0 and < 0
(eg sinking and rising), then start FLINE at 0 for both
instances- multiplying negative values by -1.


Here is an example:

 GEMPAK-GDPLOT2>l
 GDFILE   = eta
 GDATTIM  = f000
 GLEVEL   = 700
 GVCORD   = pres
 PANEL    = 0
 SCALE    = 999
 GDPFUN   = mul(omeg,-1) ! omeg
 TYPE     = f ! c/f
 CINT     = 4;4
 LINE     = 31
 FINT     = 1/1 ! 1/0
 FLINE    = 24-30;8-23 ! 0;23-8;30-24
 CLRBAR   = 1/v/ll/.005;.05 ! 1/v/ll/.005;.55/.4;.01
 TITLE    = 1/-1 ! 0
 TEXT     = .8/22/2/hw
 CLEAR    = y
 GAREA    = uslcc
 PROJ     = lcc/25;-95;25/10;0;0;0
<etc>

You could use gptext to annotate the rising and sinking color bars
accoringly.

Steve Chiswell
Unidata User Support


On Wed, 25 Apr 2001, hardimanm wrote:

> Hey folks,
> 
> I've been building scripts to automate the development of forecast model
> fields for web use at Lyndon State College, and have been attempting to
> customize certain things.  One example is with the 700mb/UVV fields
> (example at http://apollo.lsc.vsc.edu/data/web/models/eta/700/06.gif,
> http://apollo.lsc.vsc.edu/data/web/models/eta/700/00.gif ).  What I
> would like to do is to force the yellow color onto the 4-5 field, and
> have the other colors in the list all fall into place around that,
> repeating if necessary.  Right now, the whole color scheme shifts
> depending on what values are present.
> 
> For a current temperature chart, I locked in values using the following
> input:
> 
> FINT
>     = -30;-25;-20;-15;-10;-5;0;5;10;15;20;25;30;35;40;45;50;55;60;65
>  FLINE    = 0;2-21
> 
> and ran the gdcntr program twice, to cover a range of temperatures
> from -30 to 140.  I'd like to avoid this, and I think there must be an
> easier way than listing every value in FINT.  Currently, I'm using the
> following input:
> 
> gdcntr << EOF
> 
> GDFILE=   $GDFILE
> GDATTIM=  f$FORECAST
> GLEVEL=   700
> GVCORD=   pres
> PANEL=    0/0
> SCALE=    999
> GFUNC=    mul(OMEG,-1)
> CTYPE=    c/f
> CINT=     1
> LINE=     0
> HILO=
> HLSYM=
> REFVEC=
> TITLE=    1/-2/ETA 700mb Vertical Velocity (-ub/s) and Heights (m)
> TEXT=     1/3//HW
> CLEAR=    NO
> GAREA=    17;-116;52;-50
> PROJ=     STR/90.0;-95.0;0.0
> MAP=      30
> \$MAPFIL= HIPOWO.CIA
> LATLON=   0
> DEVICE=   GF|$SAVEDIR/$FORECAST.gif|766;587
> CONTUR=   3/3
> SKIP=     0
> FINT=     1/-20/4;5;1/6/40
> FLINE=    2-7;8;9-26
> CLRBAR=   1/V/LL/.002;.05//
> 
> I attempted to force color 8 onto value 5, (color 8 is forced to yellow
> using gpcolor later in the script), but it doesn't work.  Is there an
> easier way to achieve what I'm trying to do?  I'd like to avoid having
> to list every value on FINT, since there is a 1 unit increment, and the
> list would likely run too long for gempak's input, and I'd end up having
> to run gdcntr some 3 or 4 times just to get the UVV plotted.
> 
> Thanks for any help!
> 
> -Mike Hardiman
> 
>