<div class="gmail_quote">2012/6/27 Novalio Daratha <span dir="ltr"><<a href="mailto:novatha@gmail.com" target="_blank">novatha@gmail.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi,<br>have you take a look at pyomo? <br>Novalio<br></blockquote><div><br>Thank you.. I'm having a look to it, but on this page it is stated that pyomo works only for linear problems:<br><a href="http://www.coin-or.org/projects/Coopr.xml">http://www.coin-or.org/projects/Coopr.xml</a><br>
[...]Coopr
supports a diverse set of optimization capabilities that can be used to
formulate and analyze optimization applications. In particular, it
include Pyomo, a Python-based modeling tool that can model <b>abstract
linear and integer programs</b>.[...]<br><br>On the available solver list (<a href="https://software.sandia.gov/trac/coopr/wiki/GettingStarted/Solvers">https://software.sandia.gov/trac/coopr/wiki/GettingStarted/Solvers</a>) I can read only of linear or quadratic solvers, and there isn't IPOPT, that having tested it in GAMS, is known to work well for my model.<br>
<br>Antonello<br> <br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br><div class="gmail_quote"><div><div class="h5">On Wed, Jun 27, 2012 at 1:17 PM, Antonello Lobianco <span dir="ltr"><<a href="mailto:antonello@lobianco.org" target="_blank">antonello@lobianco.org</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5">Hi, thanks for your quick answer. <br>About specifying the derivatives for the Jacobian and the Hessian I was planning to use some AD packages, like ADOL-C.<br>
My needs for C++ are of two different nature:<br>1st) Aside the part of the model that is optimised we have other parts of the model that aren't. These are getting bigger and bigger and simply GAMS is not even closes to the functionality/<span lang="en"><span>expressiveness/modularity</span></span> provided by a generic programming language.<br>
Of course a second option that I may have is to leave the optimisation part in GAMS (or AMPL) and then simple update the data and call gams.<br>However this lead to the second point:<br>2nd) I'd like this model to be freely available and that people/organisations doesn't need to have a licence for a XY program in order to be able tu run it. Currently to best of my knowledge there are no "free" versions of programs that translate a model from a simple-to-write mathematical formulation to the format required by nonlinear solvers. If you know any, please step in :-)<span><font color="#888888"><br>
<br>Antonello</font></span><br></div></div></blockquote></div></blockquote></div><br>-- <br>Antonello Lobianco<br>INRA, Laboratoire d'Economie Forestière<br>14 Rue Girardet - 54000 Nancy, France<br>Tel: +33.652392310<br>
Email: <a href="mailto:antonello.lobianco@nancy-engref.inra.fr" target="_blank">antonello.lobianco@nancy-engref.inra.fr</a><br><a href="http://antonello.lobianco.org/" target="_blank">http://antonello.lobianco.org</a><br>