Re: 'sqp' error state equal to 0 - what does it mean?

[Francesco Potortì]

>In my current project I extensively use the minimization function 'sqp'.
>This function returns in the variable 'info' the error state after its
>execution. From the documentation I read that:
>
>"""
>The value returned in info may be one of the following:
>101    The algorithm terminated because the norm of the last step was less than
>tol * norm (x)) (the value of tol is currently fixed at sqrt (eps)—edit
>‘sqp.m’ to modify this value.

This should mean that convergence was achieved.

>102    The BFGS update failed.

Don't know what it means, but looks lie an error.

>103    The maximum number of iterations was reached (the maximum number of
>allowed iterations is currently fixed at 100—edit ‘sqp.m’ to increase this
>value).

No convergence was achieved within the max number of iterations.

>I call 'sqp' many times and I get 'info = 101' most of the times.

I would say that this is normal and good.

>However, sometimes I obtain 'info = 0' (zero). When this happens,
>though, the result of 'sqp' does not look 'strange'.
>
>Does anybody know what does this mean?

If the question is specifically about return value of 0, sorry, I have no idea.

-- 
Francesco Potortì (ricercatore)        Voice: +39 050 315 3058 (op.2111)
ISTI - Area della ricerca CNR          Fax:   +39 050 315 2040
via G. Moruzzi 1, I-56124 Pisa         Email: address@hidden
(entrance 20, 1st floor, room C71)     Web:   http://fly.isti.cnr.it/