[boost] [linear algebra] - question to David Abrahams

From: Janek Kozicki (janek_listy_at_[hidden])
Date: 2006-07-10 20:15:03

Hello,

Not so long ago you have mentioned that you are working on a linear
algebra library. I'm very interested in this topic, because I'm using
such library in my project.

I have looked into the vault but couldn't find this library. Can we have
a sneak peek?

Questions:

1. will your library provide functions useful when working with small
vectors like: cross_product(), dot_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.

Following functions would be needed:

operator*(vector<3,T1>,quaternion<T2>)  // most important
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()

and few others. Similar functionality is already in boost vault:
directory "Math - Numerics", file Quaternion.h

Without quaternion rotations this linear algebra library would be pretty
useless for me, so I hope it'll be there :)

-- 
Janek Kozicki                                                         |