Re: sparse is_symmetric functions

[David Bateman]

John W. Eaton wrote:
> On  4-Dec-2006, David Bateman wrote:
> 
> | While starting to write svds I found that I need to check if a matrix
> | passed to eigs is symmetric, rather than symmetric with a positive
> | diagonal as the cheap test for positive definite matrices does. At the
> | moment eigs uses arpack's dseupd only for real positive definite
> | matrices, where in fact it could use and should use it for the case of
> | [sparse(size(A,1),size(A,1)),A;A',sparse(size(A,2),size(A,2))] as
> | created by svds. I therefore need the is_symmetric function of the
> | Matrix and SparseMatrix classes.
> | 
> | However, the current sparse is_symmetric is very inefficient. The
> | attached patch makes this method of the Sparse classes much better.
> 
> OK, please check in these changes.
> 
> Thanks,
> 
> jwe
> 

Done.

D.