Hello Hartwig First, I didn't have a chance to look at your attached files. But hopefully this post is on the right track!
You could try writing a custom interface class to sit between the GLPK API recovery calls and the rest of your program. I use one for my C++ energy system simulation, named class 'SolverIf'. This kind of abstraction also enables one to include some smarts, both when building the problem (integrity tests, say) and when recovering the results (bundled into vectors, say). (Some of the intelligence I first coded in is no longer needed because the GLPK APIs have become smarter themselves over time.) One advantage (for me) is that the problem size need not be specified in advance -- you just keep plying the 'SolverIf' object with data. Perhaps you don't need this flexibility. I also put in some calls in to control the information GLPK streams to the terminal in a convenient fashion. You many wish to write classes to read in data and, on completion, write out data at various levels of resolution. I use my own data model, which was originally going to be XML based, but ended up being textual (partly because text is easier to hand-edit). You are welcome to my C++ source files for 'SolverIf'. They are well documented and cleanly coded and might provide some clues for a similar design in Java. I would suggest some insight into object-oriented design if you wish to head down this route. Good luck, Robbie --- Robbie Morrison PhD student -- policy-oriented energy system simulation Technical University of Berlin (TU-Berlin), Germany University email (redirected) : [email protected] Webmail (preferred) : [email protected] [from IMAP client] > ------------------------------------------------------------ > To: <[email protected]> > Subject: [Help-glpk] Java interface to GLPK - accessing result values > Message-ID: <[email protected]> > From: "Prof. Hartwig Baumgaertel" <[email protected]> > Date: Tue, 10 Feb 2009 16:13:34 +0100 > ------------------------------------------------------------ > > Hi all, > > I plan to use GLPK by a Java application. I'm happy > about the SWIG-based Java API - many thanks to Xypron. > > My application will use a predefined (MIP) model but > dynamically created data. There are several > possibilities to feed the data to the problem object, > so far so good. (For sake of simplicity I use a data > file in my example, too.). > > My question is about the step after solving the > model. I want to further use the result values (values > of decision variables after successful model solve) in > my Java application. I created a solution which avoids > files and databases. > > I would like to know how you experts look to this > approach, and would appreciate any suggestions and > improvements. > > I have no idea if it is trivial, stupid or the intended > way to do this. I also have no idea if there are > pitfalls regarding memory usage, efficiency etc. > > Thank you in advance! > > Hartwig _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
