Re: [Matplotlib-users] switching between color and grayscale

Is there a similar dictionary for linetypes?  I would anticipate
needing to use more linetypes in grayscale than in color (i.e.
everything could be solid in color).

Thanks again,

Ryan

On 4/17/06, Ryan Krauss <rya...@gm...> wrote:
> I am making some progress.  The following script works, but you have
> to shut down ipython if you want to switch from color to grayscale:
>
> from numpy import arange, sin, cos, pi
> import matplotlib.colors
> reload(matplotlib.colors)
> cnames=3Dmatplotlib.colors.cnames
> from pylab import figure, show, nx, clf, cla
> fig =3D figure(4)
> ax =3D fig.add_subplot(111)
> t=3Darange(0,1,0.01)
> y=3Dsin(2*pi*t)
> grayscale=3D0
> if not grayscale: # using color
>     cnames['mygreen'] =3D '#008000'
> else: # using grayscale
>     cnames['mygreen'] =3D '#808080'
>
> #ax.plot(t,y, color=3Dcnames['green'])
> ax.plot(t,y, color=3D'mygreen')
> show()
>
> Is there some command to refresh the system color dictionary?
>
> Thanks,
>
> Ryan
>
> On 4/17/06, John Hunter <jdh...@ac...> wrote:
> > >>>>> "Ryan" =3D=3D Ryan Krauss <rya...@gm...> writes:
> >
> >     Ryan> I am mildly concerned about how my plots will look if
> >     Ryan> someone prints my thesis out in grayscale.  Is there an easy
> >     Ryan> way to use the same code with one switch at the beginning to
> >     Ryan> plot in color or grayscale?  Is there a way to redefine what
> >     Ryan> happens when I call plot(x,y,'g-') so that 'g-' no longer
> >     Ryan> means green but now means something like color=3D0.75 so some
> >     Ryan> grayscale specification?
> >
> > That is an interesting problem I hadn't considered before.  We have *a
> > lot* of colors defined in matplotlib.colors.  cnames is a dict from
> > color names to rgb tuples (see below for example usage).
> >
> > It would be useful to support custom colors in the rc file or
> > elsewhere -- then you could do something like
> >
> >   colors.mygreen  : 008000
> >
> > and later redefine it to gray if you need to
> >
> >   colors.mygreen  : 808080
> >
> > But you can't do that today...  What you can do is manipulate the
> > cnames dict.  I suggest creating a module like mycolors that extends
> > the cnames dict, and then using these custom color names in your
> > script.  When you want to go grayscale, you just modify the colors in
> > mycolors.
> >
> >
> >     # mycolors.py
> >     from matplotlib.colors import cnames
> >     if 1: # using color
> >         cnames['mygreen'] =3D '#008000'
> >     else: # using grayscale
> >         cnames['mygreen'] =3D '#808080'
> >
> >
> > Then later, you can use it as follows:
> >
> >     import mycolors
> >     from pylab import figure, show, nx
> >     fig =3D figure()
> >     ax =3D fig.add_subplot(111)
> >     ax.plot((1,2,3), color=3D'mygreen')
> >     show()
> >
> > so you'll only have a single point of maintenance.  We'll also accept
> > a patch to the rc system to support custom colors, which is the
> > preferred way to go.
> >
> > JDH
> >
>