Re: [boost] [pqs] [vectors]

From: Janek Kozicki (janek_listy_at_[hidden])
Date: 2006-06-21 19:25:14

David Abrahams said:     (by the date of Sun, 18 Jun 2006 19:10:11 -0400)

> I don't think that's an improvement, if you're working with matrices
> too.  Sounds like linear algebra to me.
> 
> My library is designed to work with fixed- as well as variable-sized
> structures, and it should be possible to use fusion to build
> heterogeneous vectors and matrices compatible with my library, so I
> hope no extra library will be needed.

Hello David,

can we have a sneak peek at your library? I have looked into the vault
but couldn't find it. I also would be very happy to help you working on it.

I have few concerns here, and would be grateful if you'd answer that:

1. will your library provide functions useful when working with small
vectors like: cross product, normalize (scale vector so its length==1),
norm (returns squared length), length, etc... ?

2. will your library allow Boost.Quaternions to be extended in a way that
those two libraries together will be useful for geometrical rotations?

3. will your library provide a way to solve equation Ax=b (A is matrix,
b and x are vectors, and x is the unknown).

The background for question 2 above:

Author of Boost.Quaternions tried to extend the library with code that
would allow geomtetrical rotations, but at that time only Boost.Ublas
library was available. After some investigation he discovered that
matrices and vectors from ublas are unsuitable for the task, and finally
he gave up.

Boost.Quaternions would then have following functions added:

from_rotation_matrix(matrix<3,3,T>)
to_rotation_matrix()
from_axis_angle(vector<3,T1> axis, T2 angle)
to_axis_angle()
to_euler_angles()
operator*(vector<3,T1>,quaternion<T2>)

and few others.

-- 
Janek Kozicki                                                         |