Originally posted by: SystemAdmin

Hi,

is there a CPLEX-parameter-setting in ILOG-Script (or in the ops-file) such that I can see the choosen branching variable (e.g., in the engine log)?

Thanks & regards
Norbert
#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

have you tried

mipinterval ?

This controls the frequency of node logging when the MIP display parameter (MIP node log display information) is set higher than 1 (one). Frequency must be an integer; it may be 0 (zero), positive, or negative.

In the .ops editor, this is called MIP node log interval and in scripting you can use cplex.mipinterval

Regards
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

Hi Alex,

yes I did. I have set

cplex.mipdisplay  = 3;   
// MIP node log display information cplex.mipinterval = 1;  
// Controls the frequency of node logging when the MIP display parameter is set higher than 1.

but this just yields the follwowing output:

Tried aggregator 3 times. MIP Presolve eliminated 25155 rows and 27983 columns. MIP Presolve modified 13450 coefficients. Aggregator did 1515 substitutions. Reduced MIP has 5313 rows, 10781 columns, and 113087 nonzeros. Reduced MIP has 9967 binaries, 814 generals, 0 SOSs, and 0 indicators. Probing fixed 2 vars, tightened 0 bounds. Probing removed 2 nonzeros. Probing time =    1.47 sec. Tried aggregator 2 times. MIP Presolve eliminated 11 rows and 28 columns. MIP Presolve modified 8 coefficients. Aggregator did 4 substitutions. Reduced MIP has 5298 rows, 10749 columns, and 111175 nonzeros. Reduced MIP has 9935 binaries, 814 generals, 0 SOSs, and 0 indicators. Presolve time =    4.24 sec. Probing time =    0.34 sec. Clique table members: 51244. MIP emphasis: integer feasibility. MIP search method: dynamic search. Parallel mode: deterministic, using up to 2 threads. Root relaxation solution time =   24.49 sec.   Nodes                                         Cuts/  Node  Left     Objective  IInf  Best Integer    Best Bound    ItCnt     Gap   0     0      306.9775   771                    306.9775       19 0     0      312.0588   500                    Cuts: 65     6104 0     0      314.8704   583                    Cuts: 57    11296 0     0      315.0098   528                    Cuts: 50    15164 Heuristic still looking. Heuristic still looking. Heuristic still looking. Heuristic still looking. Heuristic still looking. *     0+    0                      5.20002e+007      315.0098    15164  100.00% 0     2      315.0098   528  5.20002e+007      315.0098    15164  100.00% Elapsed real time = 234.98 sec. (tree size =  0.02 MB, solutions = 1) 1     3      315.0098   536  5.20002e+007      315.0098    18374  100.00% 2     4      315.0098   546  5.20002e+007      315.0098    21117  100.00% 3     5      317.5297   585  5.20002e+007      315.0098    24668  100.00% 4     6      315.0098   551  5.20002e+007      315.0098    27300  100.00% 5     7      315.2119   561  5.20002e+007      315.0098    30086  100.00% Cliques: 2 6     8      315.2119   535  5.20002e+007      315.0098    31600  100.00% 7     9      315.2119   622  5.20002e+007      315.0098    35053  100.00% 8    10      315.2188   552  5.20002e+007      315.0098    44511  100.00% 9    11      315.2119   557  5.20002e+007      315.0098    49137  100.00% 10    12      315.4667   471  5.20002e+007      315.0098    54832  100.00% Elapsed real time = 299.76 sec. (tree size =  0.03 MB, solutions = 1)   
// .... etc.

Thus, no branching variable is displayed ...

Redirecting the engine log to a file results in the same output.

Regards
Norbert
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

The "problem" here is dynamic search.
If dynamic search is enabled then no branching variables are displayed. If you want to see them then you have switch the MIP search strategy to "traditional branch and cut".
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

Hi Daniel,

thanks - that solves the problem !!!

Regards
Norbert
#DecisionOptimization
#OPLusingCPLEXOptimizer