slepc-main 2024-12-17

DSCond

Compute the condition number.

#include "slepcds.h" 
PetscErrorCode DSCond(DS ds,PetscReal *cond)

Logically Collective

	ds	- the direct solver context
	cond	- the computed condition number

In standard eigenvalue problems, returns the inf-norm condition number of the first matrix, computed as cond(A) = norm(A)*norm(inv(A)).

In GSVD problems, returns the maximum of cond(A) and cond(B), where cond(.) is computed as the ratio of the largest and smallest singular values.

Does not take into account the extra row.

advanced