"David G. Johnston" <david.g.johnston@gmail.com> writes:
> It is basically treating the points as if they were a representation of
> complex numbers with x being real and y being imaginary.
Hah! I was too focused on looking for definitions involving vectors,
and didn't think of plain ol' complex numbers. But yes, that's exactly
what it is. I'll go improve the docs.
regards, tom lane