Is it known that the inv operator in Matlab 2014b is not working correctly?

Is it known that the inv operator in Matlab 2014b is not working correctly? What to do? If that is not known I can provide the proof.

[Russell]

I should have mentioned that I ran exactly the same function using Matlab 2012b and the inverse was perfect! But it is flawed using 2014b. The condition number (rcond) was about 1e-12. These have been working fine for me.

[Russell]

OK, I replaced Gi = inv(G) with Gi = G\( eye(size(G,1)) ) and things seem to be working again. The inverse looks clean. But in Matlab 2012b inv worked just as well---not in 2014b.

[John D'Errico]

This seems like a troll: you have made a silly claim, then failed to back it up, claiming only that you CAN prove there is a problem.

In fact, inv works fine. Perhaps it is your understanding of why one should not invert nearly singular matrices that needs work, or why one should avoid use of inv completely.

Answer 1

[Azzi Abdelmalek]

cond(A)

will let you know if your matrix is well conditionned

[Azzi Abdelmalek]

If rcond is near 0, that means your matrix is badly conditioned