I’m coding a math model using gurobiy, but an error occurs.
the error is ‘Var’ object cannot be interpreted as an integer.
i tried to solve it using search, but I don’t have enough information.
spi: required space of block i
cft: area of factory f at t time
s_Time : Start time
p_Time : processing time
c_Time : completion time,
yif : If blcok i is assgined at factory f 1 otherwise 0
Space must be available for the time the block is assembled before the block can be allocated to the factory.
for i in range(num_Block+1): s_Time[i] =m.addVar(lb=0,vtype=GRB.INTEGER,name='s_time'+str(i)) c_Time[i] =m.addVar(lb=0,vtype=GRB.INTEGER,name='c_time'+str(i)) for i in range(1,num_Block+1): m.addConstr(s_Time[i]+p_Time[i]==c_Time[i]) # This part occurs error because of s_Time[i],c_Time m.addConstrs(sp[i]*y[i,f] <=c[f,t] for f in range(1,num_Factory+1) for i in range(1,num_Block+1) for t in range(s_Time[i],c_Time[i]))
Gurobi is for linear (and quadratic) models. You cannot use a variable as a limit for indexing (that would make the model nonlinear). In general, such constructs are reformulated using binary variables or indicator constraints. You may want to discuss this with your teacher/supervisor.