lp_solve 中的严重错误?
dramatic error in lp_solve?
我有一个简单的问题,我通过 IDE (5.5.2.0)
传递给 lp_solve
/* Objective function */
max: +r1 +r2;
/* Constraints */
R1: +r1 +r2 <= 4;
R2: +r1 -2 b1 = 0;
R3: +r2 -3 b2 = 0;
/* Variable bounds */
b1 <= 1;
b2 <= 1;
/* Integer definitions */
int b1,b2;
这个问题的明显解决方案是 3。SCIP 和 CBC 都给出 3 作为答案,但没有 lp_solve。这里我得到 2.求解器中是否存在重大错误?
提前致谢。
当我尝试时,我得到 3 作为 Obj 函数的最佳值。
Model name: 'LPSolver' - run #1
Objective: Maximize(R0)
SUBMITTED
Model size: 3 constraints, 4 variables, 6 non-zeros.
Sets: 0 GUB, 0 SOS.
Using DUAL simplex for phase 1 and PRIMAL simplex for phase 2.
The primal and dual simplex pricing strategy set to 'Devex'.
Relaxed solution 4 after 4 iter is B&B base.
Feasible solution 2 after 6 iter, 3 nodes (gap 40.0%)
Optimal solution 2 after 7 iter, 4 nodes (gap 40.0%).
Excellent numeric accuracy ||*|| = 0
MEMO: lp_solve version 5.5.2.0 for 32 bit OS, with 64 bit REAL variables.
In the total iteration count 7, 1 (14.3%) were bound flips.
There were 2 refactorizations, 0 triggered by time and 0 by density.
... on average 3.0 major pivots per refactorization.
The largest [LUSOL v2.2.1.0] fact(B) had 8 NZ entries, 1.0x largest basis.
The maximum B&B level was 3, 0.8x MIP order, 3 at the optimal solution.
The constraint matrix inf-norm is 3, with a dynamic range of 3.
Time to load data was 0.001 seconds, presolve used 0.017 seconds,
... 0.007 seconds in simplex solver, in total 0.025 seconds.
我联系了关心 lpsolve 软件的开发人员组。该错误将在下一版本的 lpsolve 中修复。
我有一个简单的问题,我通过 IDE (5.5.2.0)
传递给 lp_solve/* Objective function */
max: +r1 +r2;
/* Constraints */
R1: +r1 +r2 <= 4;
R2: +r1 -2 b1 = 0;
R3: +r2 -3 b2 = 0;
/* Variable bounds */
b1 <= 1;
b2 <= 1;
/* Integer definitions */
int b1,b2;
这个问题的明显解决方案是 3。SCIP 和 CBC 都给出 3 作为答案,但没有 lp_solve。这里我得到 2.求解器中是否存在重大错误?
提前致谢。
当我尝试时,我得到 3 作为 Obj 函数的最佳值。
Model name: 'LPSolver' - run #1
Objective: Maximize(R0)
SUBMITTED
Model size: 3 constraints, 4 variables, 6 non-zeros.
Sets: 0 GUB, 0 SOS.
Using DUAL simplex for phase 1 and PRIMAL simplex for phase 2.
The primal and dual simplex pricing strategy set to 'Devex'.
Relaxed solution 4 after 4 iter is B&B base.
Feasible solution 2 after 6 iter, 3 nodes (gap 40.0%)
Optimal solution 2 after 7 iter, 4 nodes (gap 40.0%).
Excellent numeric accuracy ||*|| = 0
MEMO: lp_solve version 5.5.2.0 for 32 bit OS, with 64 bit REAL variables.
In the total iteration count 7, 1 (14.3%) were bound flips.
There were 2 refactorizations, 0 triggered by time and 0 by density.
... on average 3.0 major pivots per refactorization.
The largest [LUSOL v2.2.1.0] fact(B) had 8 NZ entries, 1.0x largest basis.
The maximum B&B level was 3, 0.8x MIP order, 3 at the optimal solution.
The constraint matrix inf-norm is 3, with a dynamic range of 3.
Time to load data was 0.001 seconds, presolve used 0.017 seconds,
... 0.007 seconds in simplex solver, in total 0.025 seconds.
我联系了关心 lpsolve 软件的开发人员组。该错误将在下一版本的 lpsolve 中修复。