GAMS World Forum

I don't understand the question. -Michael

Gradient methods, barrier method, simplex, etc have the concept of a "moving a point through space" and hence they can talk about statistics about this "point". Global methods like branch-and-bound don't have a "point" concept and hence there is no way talking about the...

GAMS requires operators between all parts of the expression. In papers for multiplication the '*' sign is often left out. You need that in GAMS (and many other languages):
-Michael

I suggest that you look at the gdxxrw documentation (https://www.gams.com/latest/docs/T_GDXXRW.html). There are many good examples that you can follow. Reading GAMS indexed data requires the indexes (here op1*op5) to be present with the data. GAMS and GAMS tools do not read positional data.

-Michael

You sent a GDX file. Nothing I can do with this. -Michael

What is the "current feasibility of the solution"? One of the bounds give you the value of your incumbent. Some solvers also give you the number of integer infeasibilities in the log, but since BARON also needs to branch on continuous variables, this needs to be extended to the number of p...

You either introduce a binary variable b that tells you where you x is (x<=omega/alpha => b=0, else b=1) and use that to model the function or if you are in the lon-linear model realm anyway use ifthen(x<=omega/alpha, omega*x - alpha/2*sqr(x), omega/alpha).

-Michael

Numerical instabilities in an algorithm is sometimes caused by scaling issues. GAMS/Cplex has a "dataCheck=2" option (part of GAMS/Cplex option file) that can hint at model parts that can cause trouble. It is always best to "fix" things at the model level (hard to help if you can...

You should look at execute_unload (https://www.gams.com/latest/docs/UG_GDX.html#UG_GDX_WRITE_EXECUTION_EXECUTE_UNLOAD). If you want to split your existing GDX file, then use "gdxdump my.gdx noData > my.gms" to create a GAMS file my.gms that reads your entire GDX file into GAMS and then hav...

The tool gdx2access exports the entire content of a GDX file to MS-Access, no selection of symbols possible. The solution here would be to generate 5 different GDX files with one symbol per GDX and use gdx2access to create 5 MS-Access databases. You can also try the new GAMS Connect with agent panda...