Re: [ferret_users] Re: [ferret_users] For the end of the default rainbow palette !

[Ryo Furue <furue@xxxxxxxxxx>]

Hi Ferret users,

[. . .]
> But please leave the default untouched.
> Why?
> It is a rainbow. It scatters the information
> over the largest number of colors perceptable
> by our eyes.

First of all, I agree that the default shouldn't be changed.  But, my
reason is backward compatibility.

Because I think "the rainbow" can be improved.  The most important
words, to me, about the new palettes Patrick introduced are
"Perceptually Uniform".

Let's try this:

yes? let var = x[i=1:10] + y[j=1:10]
yes? fill var

Even though the field is linear, you realize that you see the color
gradient better in some parts than in others.

This is because the human eye is not linear: its sensitivity in
wavelength change isn't uniform across the color spectrum.  Other
aspects (like saturation) may be involved, too.

There seems to be a lot of research into this:

https://mycarta.wordpress.com/2012/05/12/the-rainbow-is-dead-long-live-the-rainbow-part-1/

http://peterkovesi.com/projects/colourmaps/ColourmapTheory/index.html

So, there is no reason why we should keep using the same rainbow as we
did 30 years ago, when you don't need backward compatibility.

Regards,

Ryo