Dear Rodrigo,<br>Being able to give an indication of why an MINLP is infeasible would be very nice, but unfortunately I think it is a pretty difficult problem, and I don't see anything automatic which can be put in Bonmin without a substantial amount of work.
<br><br>If you have a model which is infeasible and you think should not be, I think that a good way to start is to add artificial variables for the constraints and try to minimize constraint violation. You can then see which of the constraints seems to give the most difficulties.
<br><br>Cheers,<br>Pierre<br><div><span class="gmail_quote">On 11/21/06, <b class="gmail_sendername">Rodrigo López Negrete de la Fuente</b> <<a href="mailto:soyrush@gmail.com">soyrush@gmail.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Dear Pierre,<br><br>Now that you put it that way, I am not so sure...Although it would be helpful to try and find where the unfeasibilities are, or to get some extra information on where my problem might be. What do you think?
<br><br>cheers,<br><span class="sg"> Rodrigo</span><div><span class="e" id="q_10f0bd1884f77934_2"><br><br><div><span class="gmail_quote">On 11/21/06, <b class="gmail_sendername">Pierre Bonami</b> <<a href="mailto:pierre.bonami@gmail.com" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
pierre.bonami@gmail.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Dear Rodrigo,<br>I am not sure what the behavior should be. Since there is no known solution in this case any values are wrong. <br><br>Anyway, if the values of the last feasible Non-Linear program computed are usefull to you, I can try to plug them in. (Is that what you want?
<br><br>Cheers,<br>Pierre<br><br><div><div><span><span class="gmail_quote">On 11/19/06, <b class="gmail_sendername">Rodrigo López Negrete de la Fuente</b> <<a href="mailto:soyrush@gmail.com" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
soyrush@gmail.com</a>> wrote:</span>
</span></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div><span>Hello everybody,<br><br>I've been using bonmin through its ampl interfase. I've noticed that when the solver ends with an infeasible problem, the values of the variables are not updated, (
i.e., the values of the returned variables are the same as the initial values I supplied). I was wondering if this is normal behavior or if there is a way to get the last feasible (NLP) solution calculated.
<br><br>I'm using the BB method... Although I've seen this behavior with the other methods as well.<br><br>Thanks all,<br> Rodrigo.<br clear="all"><span><br>-- <br>Rodrigo López Negrete<br><a href="http://muon.blogdns.org/%7Erush/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
http://muon.blogdns.org/~rush/</a>
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</blockquote></div><br><br clear="all"><br>-- <br>Rodrigo López Negrete<br><a href="http://muon.blogdns.org/%7Erush/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">http://muon.blogdns.org/~rush/</a>
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