如何使用 python 運行 .mod 文件 (CPLEX)？

Question

我正在嘗試使用 CPLEX 比較 PLNE 模型的結果，並且我想使用 python 多次運行此 CPLEX 模型並比較結果。 如何在 python 中運行 .mod 文件（在 CPLEX 上創建的文件）？ 我在 python 上閱讀了關於 cplex 庫的東西，但是，如果我理解正確，它的目的是直接在 python 上制作模型......我是個菜鳥，所以任何建議都會有所幫助:)

謝謝 ！

Answer 1

最好是使用doopl包

例如，

你可以寫 zootupleset.mod

int nbKids=300;

// a tuple is like a struct in C, a class in C++ or a record in Pascal
tuple bus
{
key int nbSeats;
float cost;
}

// This is a tuple set
{bus} buses=...;

// asserts help make sure data is fine
assert forall(b in buses) b.nbSeats>0;
assert forall(b in buses) b.cost>0;

// decision variable array
dvar int+ nbBus[buses];

// objective
minimize
 sum(b in buses) b.cost*nbBus[b];

// constraints
subject to
{
 sum(b in buses) b.nbSeats*nbBus[b]>=nbKids;
}

tuple solution
{
  int nbBus;
  int sizeBus;
}

{solution} solutions={<nbBus[b],b.nbSeats> | b in buses};

然后是以下python代碼

from doopl.factory import *

# Data

Buses=[
    (40,500),
    (30,400)
    ]

# Create an OPL model from a .mod file
with create_opl_model(model="zootupleset.mod") as opl:
    # tuple can be a list of tuples, a pandas dataframe...
    opl.set_input("buses", Buses)

    # Generate the problem and solve it.
    opl.run()

    # Get the names of post processing tables
    print("Table names are: "+ str(opl.output_table_names))

    # Get all the post processing tables as dataframes.
    for name, table in iteritems(opl.report):
        print("Table : " + name)
        for t in table.itertuples(index=False):
            print(t)

        # nicer display
        for t in table.itertuples(index=False):
            print(t[0]," buses ",t[1], "seats")

給

Table names are: ['solutions']
Table : solutions
Pandas(nbBus=6, sizeBus=40)
Pandas(nbBus=2, sizeBus=30)
6  buses  40 seats
2  buses  30 seats