[Rd] plot.lm: "Cook's distance" label can overplot point labels

[John Fox]

Dear Thomas,

Though far from an expert on the matter, it's my understanding that
red-green confusion is the most common form of colour-blindness. I guess
that the best way to put it is that it would be desirable to choose colours
for the standard palette that minimize the probability of perceptual
problems.

Regards,
 John


> -----Original Message-----
> From: Thomas Lumley [mailto:tlumley at u.washington.edu]
> Sent: February-20-09 4:32 AM
> To: John Fox
> Cc: 'John Maindonald'; 'Prof Brian Ripley'; r-devel at r-project.org; 'Martin
> Maechler'
> Subject: Re: [Rd] plot.lm: "Cook's distance" label can overplot point
labels
> 
> On Thu, 19 Feb 2009, John Fox wrote:
> 
> > Dear John and Brian,
> >
> > My point about colour-blindness was partly tongue-in-cheek, but I think
> that
> > it's a bad choice to have the second and third colours in the default
> > palette as red and green.
> >
> 
> Looking at the standard palette with dichromat::dichromat() it seems that
it
> depends on which flavour of red-green anomaly you have. For deuteranopia
the
> red and green are quite close. For protanopia they are pretty distinct and
> the confusion is between colours 3 and 7 (yellow vs green) and between 4
and
> 6 (blue and magenta).
> 
> I agree that the standard palette isn't ideal, though.
> 
>       -thomas
> 
> Thomas Lumley			Assoc. Professor, Biostatistics
> tlumley at u.washington.edu	University of Washington, Seattle
>