On 20.06.06, John Owens wrote:
> --- Joerg Lehmann <[EMAIL PROTECTED]> wrote:
>
> > > 1) The one you state above; I'd advocate possibly doing a gradient
> > > between the first and last color of the most detailed palette entry
> > > (so if a palette had discrete colors for 3-10 colors, use p[10][0]
> > > and p[10][9]).
> > >
> > > 2) What happens if you don't define enough colors? For instance
> > > most of the colorbrewer schemes only start defining at 3 colors
> > > (there's no 1 or 2 color schemes). In that case if I needed only 2
> > > colors I'd want to take the first two elements of the least detailed
> > > palette entry.
> >
> > In some way your questions show that the concept becomes indeed a bit
> > shaky.
>
> Well, to be fair, with any discrete scheme this would come up. The
> first question is "is it useful to have a discrete scheme indexed by
> total number of colors and by color number?" No surprise that I think
> the answer is "yes";
When posting my initial scheme, this was also obvious to me. On the
other hand, it's not what a color palette usually means: an ordered
collection of a finite number of colors. But we could reconcile
these two pictures of a palette as described in my other mail, but
considering the trivial mapping
[[c11], [c21, c22], [c31, c32, c33], ...] ->
[c11, c21, c22, c31, c32, c33, ...]
> I think Dr. Brewer's research shows that color
> selection in general, and her schemes in particular, are
> generally useful for understanding. Then if you want to support such
> a discrete scheme, you have to handle the cases when you haven't
> defined colors. The question then is "do you leave that up to the
> programmer" or "do you handle it in some reasonable way within the
> programming system", and I'd argue for the latter in the way I described
> above.
This is something which has to be discussed (try import this and look
at line number four, counting empty lines). The needed input would
be:
- how many variants does a given scheme typically have?
- can the fall-back behaviour in the case of a variant not
exisiting for the given total number of colors be well defined, i.e.
how implicit would the choice be?
Jörg
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