[Boost-users] Re: ublas and matrix expression

From: Russell Hind (rhind_at_[hidden])
Date: 2004-04-08 07:38:24

Angus Leeming wrote:
> 
> Hi, Russell.
> 
> You are trying to solve a matrix expression.
> 
>         A = B^-1 * C*D
> is equivalent to
>         B*A = B*B^-1 * C*D
> which collapses to
>         B*A = C*D
> 
> So, you can reprase your problem as solve the system
>         B*A = E
> where B,E are known, E=C*D, to give the unknown A.
> 
> Have a look at the (undocumented :-() lu_factorize and lu_substitute 
> routines. They should enable you to complete the task.
> 

Thanks, where are these methods defined?  I'm using 1.30.2 and have 
searched the ublas directory for files with lu_factorize in and can't 
find it.

Thanks

Russell