Re: Plotting, hold-on, colors

[Ben Abbott]

On Sep 2, 2008, at 2:54 AM, Ben Boxman wrote:

> Hi,
>
>  I tried "set (gca, 'colororder', colors)", but what this seems to  
> allow me
> is to change the order of the colors as used by plot (e.g. changing  
> the
> second used color from green to red). This is isn't my problem --  
> I'm having
> a problem with "hold on".
>
>  My problem is not the actual colors in the color order, but that  
> toggling
> "hold on" will keep the same color. For instance, if I do the  
> following:
> x = [1:100]
> plot(x, sin(x), x, cos(y))
> I get a graph with sin(x) showing up with one color, and cos(y)  
> showing up
> with another (for some reason, blue and green).
>
> However, if I do:
> hold off;
> plot(x, sin(x))
> hold on;
> plot(x, sin(y))
> I get a graph with sin(x) and cos(x) sharing the same color (blue).
>
> This used to work properly in the old octave chain (i.e. 2.1.x) and  
> seems to
> be broken at least from 2.9.x.
>
> I want to use hold. It is inconvenient to:
> 1) Set colors manually for each plot.
> or:
> 2) Pass these all off as one plot.
> And -- if I'm using another function that produces a plot (e.g.  
> hist, or
> pwelch, or perhaps even one of my own) -- which I wish to  
> superimpose on
> another, it can get even more difficult.
>
>
> Many thanks,
>
> Ben Boxman

is the following to much trouble?

        hold off
        plot (x, sin(x), 'b')
        hold on
        plot (x, cos(x), 'r')

Ben