linear -> affine and shapes are immutable lucier@xxxxxx (12 Nov 2001 23:26 UTC)
Re: linear -> affine and shapes are immutable Jussi Piitulainen (13 Nov 2001 07:22 UTC)
Re: linear -> affine and shapes are immutable Brad Lucier (13 Nov 2001 08:36 UTC)
Re: linear -> affine and shapes are immutable Jussi Piitulainen (13 Nov 2001 13:14 UTC)

Re: linear -> affine and shapes are immutable Brad Lucier 13 Nov 2001 08:36 UTC

>
> xxxxxx@math.purdue.edu writes:
>
> > I would suggest that "affine" would be a better name than
> > "linear" for the properties of the access functions.  Linear
> > is OK (as in linear as opposed to quadratic polynomials), but in
> > this context with all the "vector"s and "array"s, I think affine
> > would be better.
>
> Interesting. A book on Java 2D graphics defines affine transformation
> as "one in which parallel lines are still parallel after ...".
>
> I cannot judge which is better. I don't want to put in anything about
> parallel lines. Does "each index is a sum of multiples" match "affine"
> at least as well as it matches "linear"?

An affine map is a linear map plus a constant.

Brad