CPLEX CP 调度问题：区间变量中的浮点时间

Question

I have been carrying out experiments with CPLEX ILOC CP Optimizer using **docplex for Python ** in the field of scheduling. However, as far as CPLEX doc states, interval variables must be defined by integer values (start, duration, end).

Thus, my question is about the possibility of introducing float values for times in docplex, since in my case activities average durations are defined by floating-point numbers. As far as I know, I have not found any source that talks about how to work it around.

Thanks in advance.

Answer 1

with CPOptimizer you can use decimal decision variables as a workaround.

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")