TypeError: unsupported operand type(s) for /: 'int' and 'Var'

Answered

Hernani Delgado Chantre

March 31, 2021 16:44 Edited

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Hi there, I am new in the Gurobi I need some direction on how to solve the following error: TypeError: unsupported operand type(s) for /: 'int' and 'Var'tinpsi_ui[u,i,k] = 1/psi_ui[u,i,k]

In the problem I am solving

psi_ui[u,i,k] = model.addVar(vtype=GRB.CONTINUOUS, name="psi_ui[%d,%d,%d]"%(u,i,k))

is a continuos decision variable,

tinpsi_ui[u,i,k] = model.addVar(vtype=GRB.CONTINUOUS, name="psi_ui[%d,%d,%d]"%(u,i,k))

is an auxiliary continuos decision variable,

x[u,v,i,k] = model.addVar(vtype=GRB.BINARY, name="x[%d,%d,%d,%d]"%(u,v,i,k))

is a binary decision variable

I have the following contraint:

 

\sum_{u\in U} \sum_{k=0}^{K} \sum_{i=1}^{C_u}

 (tau_v[v]/psi_ui[u,i])

 x_{uvik} \leq{L_v} \quad \forall{v}\in V

 

I code this contraint as follow:

for v in V:

        #constraint = LinExpr()      

        for u in U:

            for i in range(C_u[u]): 

                for k in range(1,K):

                    tinpsi_ui[u,i,k] = 1/psi_ui[u,i,k]

                    model.addConstr(inpsi_ui[u,i,k] == (psi_ui[u,i,k])**(-1)) 

                    constraint.add(tau_v[v]*x[u,v,i,k]*tinpsi_ui[u,i,k])

        model.addConstr(constraint <= L_v[v])

 

Thank you,

Hernani

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• Official comment

  

  Simranjit Kaur

  • Gurobi Staff

  June 23, 2025 02:57 Edited

  This post is more than three years old. Some information may not be up to date. For current information, please check the Gurobi Documentation or Knowledge Base. If you need more help, please create a new post in the community forum. Or why not try our AI Gurobot?.
• 

  Matthias Miltenberger

  • Gurobi Staff

  April 01, 2021 06:57

  Hi Hermani,

  This post should help you get started with variable divisions:
  How do I divide by a variable in Gurobi? – Gurobi Support Portal

  Cheers,
  Matthias

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