Re: [Help-glpk] Solving shortest path problem and getting wrong answer

2010-04-25 Thread Merike 
  22.04.2010 22:31, Andrew Makhorin kirjutas:
 Glpsol solves your instance correctly, so you need to check your mps
 file.

 Writing models in mps format by hand is cumbersome. You may look at
 the example model spp.mod, which solves the shortest path problem and
 is written in MathProg modeling language (see subdirectory 'examples').

Oh, I didn't generate it by hand, but programmatically. The idea of this 
task is to use equations to solve it, so I'm afraid that solving it with 
MathProg model isn't the way to go. Thanks for answering anyhow, I'll 
keep looking as to why these equations return answer with numbers less 
than minimal path for some nodes.





___
Help-glpk mailing list
Help-glpk@gnu.org
http://lists.gnu.org/mailman/listinfo/help-glpk

Re: [Help-glpk] GLPK vs. SCIP for solving MIP

2010-04-25 Thread Lifit 



Ali-
Excellent suggestion.
I followed your advice, translated into LP, and got scip to solve my
problem (with no extra settings) in less than 20min.

I also tried writing out to MPS (both wmps and freemps), but for some
reason scip produced incorrect results.


Thanks
Yaron


On Fri, Oct 2, 2009 at 4:30 AM, Ali Baharev ali.baha...@gmail.com wrote:
 Hi,

 SCIP implements more heuristics than GLPK. In certain cases this can
 make a significant difference.

 Why don't you just use GLPK to translate your GMPL model into cplex
 lp format and than use SCIP to solve that?

 In this way you do not have to learn anything new.

 Of course, you have to find the proper settings to make SCIP solve
 your problems quickly.

 Good luck,

 Ali

Hi, I just started to learn about MILP, and I am looking for informations
about
scip, Does somebody know where can i find a tutorial or a good documentation
about it?
Just for some tests that my teacher would like to do,I would like to know if
scip can understand any file .zpl 
straight away ... ?
instead of mps and lp  ???
where can i find about the line commands also ? 
for example to discover what are the ways to give a input to scip .. ?

Thanks in advance
Loreena



-- 
View this message in context: 
http://old.nabble.com/GLPK-vs.-SCIP-for-solving-MIP-tp25711644p28359292.html
Sent from the Gnu - GLPK - Help mailing list archive at Nabble.com.






___
Help-glpk mailing list
Help-glpk@gnu.org
http://lists.gnu.org/mailman/listinfo/help-glpk