我试图通过使用opl将其编写为线性程序并使用cplex studio解决它来解决网络流问题。CPLEX工作室花了26分钟解决了这个问题。但是,
Engine Log
说的是
Network time = 0.21 sec
以下内容:
CPXPARAM_LPMethod 3
Tried aggregator 1 time.
LP Presolve eliminated 914361 rows and 916674 columns.
Aggregator did 5 substitutions.
Reduced LP has 4629 rows, 457853 columns, and 913392 nonzeros.
Presolve time = 1.28 sec. (955.67 ticks)
Extracted network with 4630 nodes and 457853 arcs.
Extraction time = 0.04 sec. (22.54 ticks)
Iteration log . . .
Iteration: 0 Infeasibility = 3444.000000 (-1.21856e+06)
...
Iteration: 50000 Objective = -1158876.510000
Network - Optimal: Objective = -1.1643204900e+06
Network time = 0.21 sec. (53.14 ticks) Iterations = 54799 (15500)
我不完全确定我是否正确地阅读了日志。
这是否意味着预解析(或其他开销)需要26分钟来消除行/列等,而实际的网络求解只需要0.2秒?
如果是这样,绕过预溶剂会更快吗?(如有必要,我如何绕过预溶剂?)
