Decision Optimization

Originally posted by: KeerthivasanC

I have the following output from a model I ran in docplex.cp:

-------------------------------------------------------------------------------
Model constraints: 9, variables: integer: 20, interval: 0, sequence: 0
Solve status: Feasible, Fail status: SearchHasNotFailed
Search status: SearchCompleted, stop cause: SearchHasNotBeenStopped
Solve time: 0.02 sec
-------------------------------------------------------------------------------

TP1_0: 0
TP1_1: 2
TP1_2: 0
TP1_3: 0
TP1_4: 0
TP2_0: 0
TP2_1: 2
TP2_2: 0
TP2_3: 2
TP2_4: 0
TP3_0: 3
TP3_1: 0
TP3_2: 2
TP3_3: 0
TP3_4: 1
TP4_0: 3
TP4_1: 0
TP4_2: 3
TP4_3: 0
TP4_4: 0

I want to transform this output into a dataframe like this:

Each row will be the list of values corresponding to TPi. A code snippet which does something like this would be great because I am unable to find any resources to manipulate the result of the CP solver in python to create dataframes.

Thanks.

Hi,

let me use the zoo example as a starting point

https://www.linkedin.com/pulse/making-optimization-simple-python-alex-fleischer/

from docplex.cp.model import CpoModel

mdl = CpoModel(name='buses')

nbbus40 = mdl.integer_var(0,6,name='nbBus40')
nbbus30 = mdl.integer_var(0,6,name='nbBus30')
cost= mdl.integer_var(0,1000000,name='cost')

mdl.add(cost==nbbus40*500 + nbbus30*400)
mdl.add(cost<=4000)
mdl.add(nbbus40*40 + nbbus30*30 >= 300)

siter = mdl.start_search(SearchType='DepthFirst', Workers=1, TimeLimit=100)
# Parameters needed to avoid duplicate solutions

from pandas import *
dfsol=pandas.DataFrame()

for msol in siter:
    print(msol[nbbus40]," buses 40 seats")
    print(msol[nbbus30]," buses 30 seats")
    print("cost = ",msol[cost])
    dfsol=concat([dfsol,DataFrame([msol[nbbus40],msol[nbbus30],msol[cost]])],axis=1)
    print("\n")
dfsol.columns=["nbBus40","nbBus30","cost"]

print(dfsol)   

gives

   nbBus40  nbBus30  cost
0        3        4     6
1        6        5     2
2     3900     4000  3800

Originally posted by: KeerthivasanC

Thanks a lot for your help!

Originally posted by: ChrisBr

Hello,

In addition to Alex's answer, I would suggest you to have a look at DOcplex.CP: Constraint Programming Modeling for Python documentation, and especially the part about how to retrieve results.

Regards,

Chris.