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Re: How to load a customized color table? [message #64628 is a reply to message #64627]

Mon, 12 January 2009 10:43

Spon
Messages: 178
Registered: September 2007

Senior Member

On Jan 12, 9:26 am, RussellGrew <russell.g...@gmail.com> wrote:
> g[*] = 0.
>
> may be more appropriate.

Also completely unnecessary, as IDL will set all elements of a newly
created array to 0 by default unless you use the /NoZero keyword. I'm
also not sure what that common block is doing there, or the double
precision numbers that get turned into bytes anyway.

This is how I'd write such a procedure:

***

; OldRGB is an output variable that
; returns the previous colour table values
PRO LOADREDBLUE, OldRGB
; Store current colour table
TVLCT, OldRGB, /GET
; Generate new colour table values
R = [2B*REVERSE(BINDGEN(128)), BYTARR(128)]
G = BYTARR(256)
B = [BYTARR(128), 2B*BINDGEN(128)]
; And load them
TVLCT, R, G, B
PRINT, 'Loading table: Red-Black-Blue'
RETURN
END

***

So if you cared about turning your old colour table back on after your
call, you could use the procedure like in this example:
IDL> Device, Decomposed = 0
IDL> Image = Dist(256)
IDL> LOADREDBLUE, Previous ; load your custom table. The 'Previous'
variable contains the old table's values.
IDL> TVSCL, Image ; display the image
IDL> TVLCT, Previous ; reload the old table
IDL> Window, /Free & Plot, Image ; using previous colour table in a
new window

And if you don't care what the previous colour table looked like, just
type:
IDL> LOADREDBLUE
and you're away (assuming that, again, you've turned off decomposed
colours)
IDL> TV, Bindgen(256,256)

Regards,
Chris

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[Message index]

		Re: How to load a customized color table? By: Spon on Tue, 13 January 2009 03:07
		Re: How to load a customized color table? By: David Fanning on Mon, 12 January 2009 10:51
		Re: How to load a customized color table? By: Spon on Mon, 12 January 2009 10:43
		Re: How to load a customized color table? By: russell.grew on Mon, 12 January 2009 01:26
		Re: How to load a customized color table? By: David Fanning on Sat, 10 January 2009 09:57

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