Flag for non pos-def error matrix?


I was just wondering if there is a flag for the error matrix being non-diagonal when one performs a fit. I already know how to look for flags for convergence. Thanks in advance.

-Andrew Meade

No, it does not exist. It does not make much sense too, since it is also very rare to have zero correlations in the fit parameters.


What is the relation between a non-posdef matrix and a non-diagonal matrix ?