matplotlib

Hi Jonathan,

On Fri, Aug 20, 2010 at 16:29, Jonathan Slavin <jslavin@...> wrote:
> To all:
>
> I'm wondering if there is any way to make plots with open symbols, e.g.
> a circle.  I know how to use markers that look open, e.g. by doing
> something like,
> plot(x,y,marker='o',mfc='w')
> They are white in the center, but they're not really open since they
> block out whatever is behind them.  I tried using a color with
> transparency, say alpha=0.1 or something (mfc=(1.,1.,1.,0.1)) but that
> didn't work.  What I have in mind is illustrated in the attached plot,
> which I made some time ago in IDL. Is there an easy way to define your
> own markers for plotting?

just use mfc='None'


Tinne

Tinne,

Thanks.  I think I had tried that but with mfc=None -- that is without
None in quotes as if it were a string.  I have to say it's a bit odd to
have it in quotes since generally it is a different data type entirely
(None type).

Jon

On Fri, 2010-08-20 at 17:12 +0200, Tinne De Laet wrote:
> Hi Jonathan,
> 
> On Fri, Aug 20, 2010 at 16:29, Jonathan Slavin <jslavin@...> wrote:
> > To all:
> >
> > I'm wondering if there is any way to make plots with open symbols, e.g.
> > a circle.  I know how to use markers that look open, e.g. by doing
> > something like,
> > plot(x,y,marker='o',mfc='w')
> > They are white in the center, but they're not really open since they
> > block out whatever is behind them.  I tried using a color with
> > transparency, say alpha=0.1 or something (mfc=(1.,1.,1.,0.1)) but that
> > didn't work.  What I have in mind is illustrated in the attached plot,
> > which I made some time ago in IDL. Is there an easy way to define your
> > own markers for plotting?
> 
> just use mfc='None'
> 
> 
> Tinne
-- 
______________________________________________________________
Jonathan D. Slavin              Harvard-Smithsonian CfA
jslavin@...         60 Garden Street, MS 83
phone: (617) 496-7981           Cambridge, MA 02138-1516
 cell: (781) 363-0035           USA
______________________________________________________________

On Fri, Aug 20, 2010 at 10:25 AM, Jonathan Slavin
<jslavin@...:

> Tinne,
>
> Thanks.  I think I had tried that but with mfc=None -- that is without
> None in quotes as if it were a string.  I have to say it's a bit odd to
> have it in quotes since generally it is a different data type entirely
> (None type).
>
> Jon
>
> On Fri, 2010-08-20 at 17:12 +0200, Tinne De Laet wrote:
> > Hi Jonathan,
> >
> > On Fri, Aug 20, 2010 at 16:29, Jonathan Slavin <jslavin@...>
> wrote:
> > > To all:
> > >
> > > I'm wondering if there is any way to make plots with open symbols, e.g.
> > > a circle.  I know how to use markers that look open, e.g. by doing
> > > something like,
> > > plot(x,y,marker='o',mfc='w')
> > > They are white in the center, but they're not really open since they
> > > block out whatever is behind them.  I tried using a color with
> > > transparency, say alpha=0.1 or something (mfc=(1.,1.,1.,0.1)) but that
> > > didn't work.  What I have in mind is illustrated in the attached plot,
> > > which I made some time ago in IDL. Is there an easy way to define your
> > > own markers for plotting?
> >
> > just use mfc='None'
> >
> >
> > Tinne
> --
>


John,

This used to trip me up as well.  However, for colors in matplotlib, None
(without quotes) tells mpl to use the default color, while 'None' (typically
not case-sensitive) means "do not plot any color".

I hope that clears things up.

Ben Root

2010/8/20 Benjamin Root <ben.root@...>:
> This used to trip me up as well.  However, for colors in matplotlib, None
> (without quotes) tells mpl to use the default color, while 'None' (typically
> not case-sensitive) means "do not plot any color".

More precise, the string 'None' translates to fully transparent black,
as far as I understand.  The ps backend e.g. ignores such objects when
printing out then.

Freidrich