[Boost-users] Re: ublas and matrix expression

From: Russell Hind (rhind_at_[hidden])
Date: 2004-04-08 11:46:32

Lorenzo Bolla wrote:

> seeing the dimension of your matrix, the easiest way to do that is:
> 1. compute z = X^T y: z is 5 x 1
> 2. compute A = X^T X with prod (trans (X), X): A is 5 x 5
> 3. use LAPACK to solve: A a = z (5 x 5 linear system)
> 

Thats where I've go to, I just need the routines to solve the Aa=z.  As 
mentioned, I don't have boost-1.31.0 so I can't use the lu_* methods 
from there.  I had a quick look at the matrix template library, but 
didn't have much luck getting it to compile with Borland bcc32.  Are 
there any small, light-weight libraries out there that can solve this? 
I'd rather something that was source only (as uBlas is), so I don't have 
to build and link with another library / dll.

> ublas::solve only works for particular types of matrices (for example,
> triangular matrices - upper or lower... - like the tag...).
> 

Thanks, I've just found out what triangular matrices are :)

Cheers

Russell