Re: [Boost-users] uBLAS, Inverse of Matrices -- Urgent

From: Le Farfadet Spatial (le.farfadet.spatial_at_[hidden])
Date: 2005-01-24 06:31:55

        Hello everybody out there !

ajb_at_[hidden] a écrit :
> The reason is that while there is only one "obvious" way to multiply
> two general matrices

        Well... Not really : there is many algorithms which purpose is to speed 
up matrices multiplications, such as Coppersmith and Winnograd algorithm.

> Gaussian elimination, LU decomposition and Cramer's rule (to name but
> three) are all ways to invert a general matrix, each of which has
> different efficiency and stability properties, and which return different
> answers on the same floating point hardware.  This means that if you want
> to invert a matrix, you have to pick an algorithm appropriate to your
> problem.  It's therefore impossible to supply an operation of the form
> inverse(m) which is generally useful.

        I totaly agree with it.

        Best regards.

                                                        Yoann LE BARS