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<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;">Hi,<br>
<br>
Thank you for your response. Just for sake of completeness on this topic: the documentation mentions x_new as:
<div><br>
<i>"new_x: (in), false if any evaluation method was previously called with the same values in x, true otherwise."</i>
<div><i><br>
</i></div>
<div>I will investigate how to implement this for my particular case.</div>
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<div>Best regards,</div>
<div><br>
</div>
<div>-Martijn</div>
<div><i><br>
</i>________________________________________<br>
Van: Stefan Vigerske [stefan@math.hu-berlin.de]<br>
Verzonden: maandag 10 september 2012 10:39<br>
To: Martijn Disse<br>
Cc: ipopt@list.coin-or.org<br>
Onderwerp: Re: [Ipopt] Algorithm flow calling f(x) and g(x), same decision variables?<br>
<br>
Hi,<br>
<br>
I think Ipopt does not want to give promises on which order functions<br>
are evaluated.<br>
You can check the newx flag that is passed with each function evaluation<br>
to see whether *some* evaluation function has been called for the same<br>
point already.<br>
<br>
Stefan<br>
<br>
On 09/10/2012 10:12 AM, Martijn Disse wrote:<br>
> Dear all,<br>
><br>
> In both my cost and constraint function I simulate the same system with an input based on the decision variables and some other non-varying user data.<br>
><br>
> In the case when the cost and constraint function are called with the same decision variables, to avoid redundant computations, I would would not like to simulate the system twice, but only once.<br>
><br>
> I want to use a userdata structure to pass on the simulation results from cost to constraints or vice versa. Therefore I am trying to find out how the algorithm flow works:<br>
><br>
> Does the IPOPT flow ever call cost and constraint with the same decision variables? If so, which one is called first?<br>
><br>
> I have modified the hs071 example and I found out that the constraint function is called first and then the cost function is called with the same decision variables. Is this generally the case?<br>
><br>
> I have looking into the publications, but was not very succesfull in finding an answer to my question. I am guessing it is quite a common problem, that why I am asking you :).<br>
><br>
> I appreciate you help,<br>
><br>
> Best regards,<br>
><br>
> Martijn Disse<br>
><br>
><br>
><br>
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><br>
<br>
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