mldivide condition number

Hi!

I notice that matlab calculates the condition number when it runs mldivide. In cases the matrix is singular it provides a warning in the screen. Is it possible to have the condition number from the mldivide function itself? This is because in my code the matrix operation is calculated thousands of times, and whenever the condition number indicates the matrix is close not to being invertible I need to automatize the end of a loop. Currently I calculate the condition number explicitly, but I want to improve the efficiency of the code.

Answer 1

[Oleg Komarov]

No you cannot.

Explicitly means you are using cond?

Did you try the profiler to check where are the bottlenecks?

[gabriel villalobos]

Thanks for the answer. I am using condest, since the matrix is sparse.

Answer 2

[Titus Edelhofer]

Hi,

have you tried to play around with lastwarn? Find out if your mldivide produced a warning and react to this one? Or do you need this before doing the mldivide?

Titus