我想添加这组约束:
-M(1-X_(i,j,k,n) )≤S_(i,j,k,n)-ToD_(i,j,k,n)≤M(1-X_(i,j,k,n) ) ∀i,j,k,n
其中 M 是一个大数,S 是一个整数变量,取值介于 0 和 1440 之间。ToD 是一个 4 维矩阵,它从 Excel 工作表中取值。X i 对偶变量,取值 0-1。
我尝试在代码中实现如下:
for n in range(L):
for k in range(M):
for i in range(N):
for j in range(N):
if (i != START_POINT_S & i != END_POINT_T & j != START_POINT_S & j != END_POINT_T):
prob += (-BIG_NUMBER*(1-X[i][j][k][n])) <= (S[i][j][k][n] - ToD[i][j][k][n]), ""
和另一个约束如下:
for i in range(N):
for j in range(N):
for k in range(M):
for n in range(L):
if (i != START_POINT_S & i != END_POINT_T & j != START_POINT_S & j != END_POINT_T):
prob += S[i][j][k][n] - ToD[i][j][k][n] <= BIG_NUMBER*(1-X[i][j][k][n]), ""
根据我的经验,在代码中,这两个约束完全等同于我们想要的。问题是 PuLP 和 CBC 不会接受它们。产生以下错误:
纸浆:
Traceback (most recent call last):
File "basic_JP.py", line 163, in <module>
prob.solve()
File "C:\Users\dimri\Desktop\Filesystem\Projects\deliverable_B4\lib\site-packa
ges\pulp\pulp.py", line 1643, in solve
status = solver.actualSolve(self, **kwargs)
File "C:\Users\dimri\Desktop\Filesystem\Projects\deliverable_B4\lib\site-packa
ges\pulp\solvers.py", line 1303, in actualSolve
return self.solve_CBC(lp, **kwargs)
File "C:\Users\dimri\Desktop\Filesystem\Projects\deliverable_B4\lib\site-packa
ges\pulp\solvers.py", line 1366, in solve_CBC
raise PulpSolverError("Pulp: Error while executing "+self.path)
pulp.solvers.PulpSolverError: Pulp: Error while executing C:\Users\dimri\Desktop
\Filesystem\Projects\deliverable_B4\lib\site-packages\pulp\solverdir\cbc\win\64\
cbc.exe
和加拿大广播公司:
Welcome to the CBC MILP Solver
Version: 2.9.0
Build Date: Feb 12 2015
command line - C:\Users\dimri\Desktop\Filesystem\Projects\deliverable_B4\lib\sit
e-packages\pulp\solverdir\cbc\win\64\cbc.exe 5284-pulp.mps branch printingOption
s all solution 5284-pulp.sol (default strategy 1)
At line 2 NAME MODEL
At line 3 ROWS
At line 2055 COLUMNS
Duplicate row C0000019 at line 10707 < X0001454 C0000019 -1.000000000000e+
00 >
Duplicate row C0002049 at line 10708 < X0001454 C0002049 -1.000000000000e+
00 >
Duplicate row C0000009 at line 10709 < X0001454 C0000009 1.000000000000e+
00 >
Duplicate row C0001005 at line 10710 < X0001454 C0001005 1.000000000000e+
00 >
At line 14153 RHS
At line 16204 BOUNDS
Bad image at line 17659 < UP BND X0001454 1.440000000000e+03 >
At line 18231 ENDATA
Problem MODEL has 2050 rows, 2025 columns and 5968 elements
Coin0008I MODEL read with 5 errors
There were 5 errors on input
** Current model not valid
Option for printingOptions changed from normal to all
** Current model not valid
No match for 5284-pulp.sol - ? for list of commands
Total time (CPU seconds): 0.02 (Wallclock seconds): 0.02
不知道是什么问题,求大神帮忙?我是新手,如果信息不够,请告诉我应该添加什么。