suppress "Constant field. Value = 0" statement

[Dave Allured]

PS:  I see that you are already using clevs and ccols.  I failed to note
this in my first reply.

For correct usage, when using N clevs, specify N+1 ccols.  In your
sample script, you need three colors for two contour levels.  You have
only specified 2+2, missing the "top" color.  Think of the levels as the
dividing lines between the colors.

--Dave

Dave Allured wrote:

> This has been discussed several times before.  Try "set datawarn
> off".  If your results are not satisfactory, then check the GradsUsr
> archives for more details and some workarounds:
>
> http://list.cineca.it/archives/gradsusr.html
>
> Year   Subject
> ----   ------------------------------------------
> 2004   Display constant field without blanking
> 2005   FW: one contour level
> 2005   remove "Constant field. Value ="
>
> To control color with a restricted data range, use set clevs and set
> ccols for complete control over contour levels and color assignment.
> HTH.
>
> --Dave A.
> CDC/PSD/NOAA/CIRES
>
> David Westberg wrote:
>
>> How can I suppress GrADS from writing "Constant field. Value = 0" on my
>> display window?  And how can I control the color used by GrADS with a
>> constant field = 0?
>>
>> I'm trying a shaded contour of land, where land = 1 if land and land = 0
>> if water.  I represent land = 1 the color tan and land = 0 the color
>> aqua.  This works fine when just land or land and water are displayed,
>> but fails when there is just water.  When just water, the color red is
>> displayed with the "Constant field. Value = 0" statement.
>>
>> I'm contouring the NOAA/CDC NCEP/NCAR Reanalysis land.nc file.
>> My script commands follow:
>> 'set gxout shaded'
>> 'set rgb 17 225 225 180'
>> 'set rgb 18 200 255 255'
>> 'set cint 1'
>> 'set clevs 0 1'
>> 'set ccols 18 17'
>> 'd land'
>>
>> David :)
>>
>>
>
>