Hi, 

I am using Docplex to solve my CP model. I got this error, but I don't know what it means! I appreciate helping me in this regard. 

Best,

Saeede

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saeede hosseini
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#DecisionOptimization

Hi,

with CPOptimizer float decision variables are not allowed so you should try to change your variables into expressions.

See example from Making Optimization Simple with python

from docplex.cp.model import CpoModel

mdl = CpoModel(name='buses')

#now suppose we can book a % of buses not only complete buses

scale=100
scalenbbus40 = mdl.integer_var(0,1000,name='scalenbBus40')
scalenbbus30 = mdl.integer_var(0,1000,name='scalenbBus30')

nbbus40= scalenbbus40 / scale
nbbus30= scalenbbus30 / scale

 

mdl.add(nbbus40*40 + nbbus30*30 >= 310)
mdl.minimize(nbbus40*500 + nbbus30*400)

msol=mdl.solve()

print(msol[scalenbbus40]/scale," buses 40 seats")
print(msol[scalenbbus30]/scale," buses 30 seats")
​

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[Alex] [Fleischer]
[Data and AI Technical Sales]
[IBM]
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Hi,
This error is related to the CPO optimization engine (it is not specific to docplex).
I'm not sure how this error can happen in a docplex model... Can you share a small model that could reproduce this error ?
For information, there is also this slightly related discussion which may provide you with some insights how this error can happen: https://community.ibm.com/community/user/datascience/discussion/cp-optimizer-and-floating-point-variables?ReturnUrl=%2Fcommunity%2Fuser%2Fdatascience%2Fcommunities%2Fcommunity-home%2Fdigestviewer

Best regards,
Hugues

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Hugues Juille
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