Re: Change default value of system variable?

[davidf(at)dfanning.com (David Fanning)]

K. Bowman (k-bowman@null.tamu.edu) writes:

> I prefer to plot with black lines on a white background, so in my
> idl_startup file I include
> 
> !P.BACKGROUND = COLOR_24('white')    ;Set background color to white
> !P.COLOR      = COLOR_24('black')    ;Set default draw color to black
> 
> (COLOR_24 is my own routine.)
> 
> This works fine until I change plot devices and then change back, viz.
> 
> flow>idl
> IDL Version 5.3 (IRIX mipseb). (c) 1999, Research Systems, Inc.
> IDL> PRINT, !P.BACKGROUND, !P.COLOR
>     16777215           0
> IDL> SET_PLOT, 'PS'
> IDL> SET_PLOT, 'X'
> IDL> PRINT, !P.BACKGROUND, !P.COLOR
>            0         255
> 
> This means that I have to include code to set !P.BACKGROUND and
> !P.COLOR in every time I switch graphics devices. Is there any way to
> change the default value of a built-in system variable?

Uh, use somebody else's routine:

   !P.Background = FSC_Color("white", !P.Background)
   !P.Color = FSC_Color("black", !P.Color)

That will work correctly *everywhere*. :-)

Cheers,

David


-- 
David Fanning, Ph.D.
Fanning Software Consulting
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