Use option memnodes to reset to > 10000.

GAMS
1

I’m using SBB to solve a convex MINLP problem. I need to set the Nodetable limit. Becuse GAMS say Nodetable limit exceeded.
Use option memnodes to reset to > 10000. How I can fixed it can you help me?

Thanks.

İpek

2

You need to create an SBB option file (as documented here https://www.gams.com/latest/docs/UG_SolverUsage.html#BASIC_USAGE_SOLVER_OPTION_FILE). You can create this file even from within GAMS in various ways, e.g.

$onecho > sbb.opt
memnodes 1e6
$offecho
mymodel.optfile = 1;
option minlp=sbb;
solve mymodel min obj using minlp;

Hope this helps,
Michael

3

Dear Micheal, thank you so so much.
Can I ask you one more thing.
enerji 90.gms (11 KB)
The k29 constraint needs a value of 69.975 for node 0. but 34.357 in solution. I could not find the reason for this.











4

I have no idea what you are asking about. BTW, the model is an MIQCP and can be solved to global optimality in seconds by various global solvers, e.g. SCIP (see attached log).
enerji 90.log (9.5 KB)
-Michael

5

qe (0) value should be = 69.975. However, it does not give correct initial values.
In the solution(see attached log) qe (0) = 34.357 I didnt understand why?
enerji.txt (193 KB)

6

From what you sent (an lst file) it is hard to verify the solution reported by SBB. I see no obvious reason why qe(0) should be 69.975. There are multiple ways to verify that a solver reports a solution correctly, e.g. Examiner (https://www.gams.com/latest/docs/S_EXAMINER.html) or just solve a second time, turn on “option limrow=1e9;” and look at the equation listing if you see infeasibilities.

-Michael

7

Dear Micheal, thank you so much for your help. I will try it now.
I did not send it again because the file was attached in the previous message. Now in the attachment
enerji 90.gms (11 KB)
again.

8

The model does not help. I won’t occupy my machine for >2h to get to your feasible point. You can save a solution into a GDX file (and share that) via the savepoint option and share this.

-Michael