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

[Guido Walter Pettinari]

Thank you for your answer, Francesco.

I am sorry if I was not clear enough. I am aware that info=101 is good, my 
concern
is that I am getting a result (info=0) which is not contemplated by the function
documentation.

Cheers,

Guido

On 14 Apr 2010, at 15:20, Francesco Potortì wrote:

>> 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.
> 
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