Robbie, Are you telling me that an electrical engineer, to be, should or should not base his thesis on a comparison of modelling languages?
Do you agree with the papers conclusion that it is, and am I supposed to read it as: 'A thorough comparison of available modelling languages for Mixed-Integer Linear Programming'? He seems to have looked at http://www.orms-today.org/surveys/LP/LP-survey.html (we can read excel spreadsheets can we not?) and http://www.orms-today.org/surveys/LP/lp9.html. From which he concludes that mathprog has fewer features. Do you think this is sufficient? Can the model he proposes be written in Mathprog? Can it be solved by GLPK? Can you explain what the conclusion 'As the best performance was made by Zimpl, a set-oriented modelling language, it is reasonable to expect that other set-oriented languages give a similar performance. Nonetheless, this assumption was not proved.' means? - The good news is Mathprog is set oriented, but why should a matrix oriented language be less efficient? Is there not a lot of ambiguity for a comprehensive conclusion in his final conclusion: 'Zimpl generates MPS/LP files whereas the other two languages call solvers using an embedded API. Loading large models stored in MPS/LP files by appropriate solvers might be time-consuming and not as fast as using a solver API embedded into the modelling language. Another interesting question is the speed of OptimJ extraction time for MPS or LP files (for Zimpl the performance for both file formats is identical). It is also questionable whether there is a possible difference in solver computation time if different MILP problem formats are used (e.g. an MPS or LP file format).' Is loading large MPS files into GLPK time-consuming? Does GLPK’s computation time depends upon which MILP problem format is used? Perhaps languages for LP/MIP require a Chrestomathy so that we can do this research properly. -- Nigel Galloway [email protected] On Fri, Jan 20, 2012, at 11:09 PM, Robbie Morrison wrote: > > Hello all > > Those interested in a comparison between modeling > languages and translation performance may be interested > in Podhradsky (2010). GLPK MathProg is not considered > by AMPL is. > > Podhradsky, Michal. 2010. Modelling languages for > optimization -- Bachelor Thesis. Czech > Technical University in Prague, Czech Republic. > (the 'y' in 'Podhradsky' is unicode U+00FD) > > > http://support.dce.felk.cvut.cz/mediawiki/images/0/0b/Bp_2010_podhradsky_michal.pdf > > abstract (first sentence): The aim of this work is to > thoroughly compare various currently available > modelling languages for mixed-integer linear > programming (MILP), both commercial and open- source, > and eventually choose and recommend the one which is > the most suitable for the task of modelling and optimal > scheduling of cogeneration systems. > > best wishes, Robbie > --- > Robbie Morrison > PhD student -- policy-oriented energy system simulation > Institute for Energy Engineering (IET) > Technical University of Berlin (TU-Berlin), Germany > University email (redirected) : [email protected] > Webmail (preferred) : [email protected] > [from Webmail client] > > > > _______________________________________________ > Help-glpk mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/help-glpk > -- http://www.fastmail.fm - The way an email service should be _______________________________________________ Help-glpk mailing list [email protected] https://lists.gnu.org/mailman/listinfo/help-glpk
