Boost logo

Boost :

Subject: Re: [boost] Preview 3 of the Geometry Library
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2008-10-21 14:58:51

Mathias Gaunard wrote:
> - specifying the coordinate system, which also defines the dimension.

Actually, this is wrong.
It doesn't specify a coordinate system, but a geometry.

That means the topology of space gets different, and thus rules of what
objects are and can be in the space are different.

So the distance trait is no mere strategy: it actually defines the
topology of the space.
I think it should clearly be redesigned to show that we are selecting a
type of geometry, defining the space we're working on.

Instead of pythagoras/harvesine/vincenty, it should be

By the way, the objects need to be defined not only in a
dimension-agnostic way, but also in a space-agnostic way.

Apart from that, allowing multiple coordinate systems within a given
space would be fairly useless, and in Euclidian space the Cartesian
system is the best choice since it was made for algebra and computations.
For example, points expressed in polar coordinates should automatically
perform conversions from/to cartesian when using get.

Boost list run by bdawes at, gregod at, cpdaniel at, john at