Re: [Gnuplot-info] Coloring multi-column plot by column number

[Ethan M. <eam...@gm...>]

On Monday, 17 February 2020 21:43:16 PST Debostuti Ghoshdastidar wrote:
> Hi
> 
> I have a data set (input.dat) which looks as below:
> 
> #C1     C2    C3 ...   C250
> 1          -2.1    -1.9...  -1.1
> 2
> .
> .
> .
> 10       -0.9    1.3        1.7
> 
> My intention was that points 1 to 10 will be joined in each column to form
> each plot, and therefore I'll have a 249-line plot. This I am able to
> achieve by the following:
> 
> N = system("awk 'NR==1{print NF}' input.dat")
> plot for [i=2:N] "input.dat" u 1:i with lines title "" linewidth 2
> 
> Using this I obtain a plot where each line is plotted with a different
> color. I want the plots to be colored by a defined palette where the range
> is the column number itself, i.e., C2 will be the lightest blue and C250
> the darkest blue, since the columns are arranged based on a factor.

    set palette defined (0 "white", 1 "dark-blue")
    set cbrange [2:N]
    plot for [i=2:N] "input.dat" using 1:i with lines lc palette i

[oops] that should be

    plot for [i=2:N] "input.dat" using 1:i with lines lc palette cb i

The keyword "cb" means to map the palette through the colorbox range.

	Ethan