Re: color loop for gd.trm

[Ethan M. <merritt@u.washington.edu>]

On Monday 10 October 2005 10:42 pm, Shigeharu TAKENO wrote:
> 
> | From: Ethan Merritt <merritt@u.washington.edu>
> | Could you please explain why or when this is needed?
> 
> This patch is for user who want the same color behavior in png 
> term as in x11 term (or win term) without setting
> 
>   set term png xffffff x000000 x404040 \
>   xff0000 x00ff00 x0000ff xff00ff x00ffff xa0522d xffa500 xff7f50 \
>   xff0000 x00ff00 x0000ff xff00ff x00ffff xa0522d xffa500 xff7f50 \

I see.  That is different from what I understood at first.

So your goal is not to reduce the total number of colors, instead
it is to have the same default colors on all terminals?
Bastian Maerkisch <bma...@we...> has recently raised this
same issue on the mailing list.

My feeling is that the default colors on different terminal types
should *not* be the same, because each terminal has its own set
of visual properties.  For instance, yellow lines on white paper are
not easy to see - so why should PostScript or pen-plotter drivers
include yellow as one of the first 6 colors?

But I agree that the user should be able to request a particular set
of colors even if they are not the default. That is one reason I
wanted to introduce rgb colors to the core gnuplot code.
    plot <foo> with lines lc rgb 'yellow'
now plots a yellow line on any terminal that supports rgb
colors, regardless of whether it is one of the default colors.

Please look again at the 2nd plot in the demo script "rainbow.dem",
which shows how to define a spectrum of line styles that will be
the same on all terminals.

The piece that is still missing is a command that tells gnuplot to
cycle through line *styles* rather than line *types* by default.
There should be a new command so that
	set style line 1 lc rgb "purple"
	set style line 2 lc rgb "yellow"
	set <some_command_that_does_not_exist_yet>
	plot sin(x), cos(x)
uses linestyle 1 for sin(x) and linestyle 2 for cos(x) so
that the plot is purple and yellow, instead of red and green. 

Would this provide what you want?


> We found some requests on "Gnuplot Q&A board"
> http://ayapin.film.s.dendai.ac.jp/cgi-bin/trees.cgi  
> (in Japanese)

Thank you for relaying requests from that group.
I will try to look there if you point out specific requests,
but I can't read Japanese well enough or fast enough to monitor
it regularly. 



-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195