Re: octave can not solve x=A\B, but freemat can

[c.]

On 1 Apr 2014, at 18:01, TDylan <address@hidden> wrote:

> I am into a 1D-FE consolidation model and am quite surprise to see that the 
> linear system based on sparse coefficient Matrix A and RHS-vector B cannot be 
> solved by octave but without any problem in freemat. 
> 
> Apparently freemat investigates the structure of A and chooses the "right" 
> solver for the specific matrix. Octave instead gives me warnings: 
> 
> "octave warning: inverse: matrix singular to machine precision, rcond = 0"
> 
> However I have no idea how to find the "right" solver for this quite simple 
> operation x=A\B.
> 
> Is there a way to tell octave, the way it works on freemat,  to look for the 
> most appropriate solver?
> 
> Any hints highly appreciated!
> 
> tom

Have you read the manual?
http://www.gnu.org/software/octave/doc/interpreter/Techniques-Used-for-Linear-Algebra.html#Techniques-Used-for-Linear-Algebra

I cannot tell for sure without seeing your matrix, but I suspect it falls under 
case 4.

c.