Node Log |
The following information about the status of the branch-and-bound algorithm is printed in the node log:
indicates the sequence number of the current node in the search tree.
indicates the current number of active nodes in the branch-and-bound tree.
indicates the number of feasible solutions found so far.
indicates the best upper bound (assuming minimization) found so far.
indicates the best lower bound (assuming minimization) found so far.
indicates the relative gap between BestInteger and BestBound, displayed as a percentage. If the relative gap is larger than 1,000, then the absolute gap is displayed. If no active nodes remain, the value of Gap is 0.
indicates the elapsed real time.
The PRINTFREQ= and PRINTLEVEL2= options can be used to control the amount of information printed in the node log. By default a new entry is included in the log at the first node, at the last node, and at 100-node intervals. A new entry is also included each time a better integer solution is found. The PRINTFREQ= option enables you to change the interval between entries in the node log. Figure 11.4 shows a sample node log.
NOTE: The problem ex1data has 10 variables (0 binary, 10 integer, 0 free, 0 |
fixed). |
NOTE: The problem has 2 constraints (2 LE, 0 EQ, 0 GE, 0 range). |
NOTE: The problem has 20 constraint coefficients. |
NOTE: The OPTMILP presolver value AUTOMATIC is applied. |
NOTE: The OPTMILP presolver removed 0 variables and 0 constraints. |
NOTE: The OPTMILP presolver removed 0 constraint coefficients. |
NOTE: The OPTMILP presolver modified 0 constraint coefficients. |
NOTE: The presolved problem has 10 variables, 2 constraints, and 20 constraint |
coefficients. |
NOTE: The MIXED INTEGER LINEAR solver is called. |
Node Active Sols BestInteger BestBound Gap Time |
0 1 3 85.0000000 178.0000000 52.25% 0 |
0 1 3 85.0000000 88.0955497 3.51% 0 |
0 1 3 85.0000000 87.8923914 3.29% 0 |
0 1 4 86.0000000 87.8372425 2.09% 0 |
0 1 4 86.0000000 87.8342067 2.09% 0 |
0 1 4 86.0000000 87.8319845 2.09% 0 |
0 1 4 86.0000000 87.7893284 2.04% 0 |
0 1 4 86.0000000 87.7891271 2.04% 0 |
NOTE: OPTMILP added 3 cuts with 30 cut coefficients at the root. |
5 0 5 87.0000000 . 0.00% 0 |
NOTE: Optimal. |
NOTE: Objective = 87. |
NOTE: The data set WORK.EX1SOLN has 10 observations and 8 variables. |