force fsolve termination if not progressing

Hi.

I'm running repeated fsolves. With bad starting points, the engine goes nowhere. I can see this looking at the output when Display is set to iter: norm of step keeps shrinking and f fails to improve. Is there a way to pass the information that Display('iter') uses to the "myfun" workspace (i.e., the function that I'm trying to solve), thus allowing me to measure if I'm making no progress and then terminate? I could of course hack into fsolve but but obviously would prefer not to if I don't have to.

Answer 1

[Alan Weiss]

Use an output function to terminate the iterations early, if you like.

Alan Weiss

MATLAB mathematical toolbox documentation

[Leo Simon]

Wonderful, exactly what I've wanted for years... thanks very much, Alan

[Leo Simon]

It would be really nice if one could condition on exitflag in state 'done'. For example, I would like to plot the history of various fields of optimValue, but only if exitflag is <= 0. (After all, no need to try to debug if exitflag=1). But by default, at least, the output function doesn't seem to know what exitflag is in state 'done', (which seems very odd). So my question is, is there a way to pass exitflag to my output function?

Thanks! Leo