Constraint has no bool value (are you trying "lb <= expr <= ub"?)

Answered

Yunus Emre Çakır

January 26, 2024 10:32

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I have the following decision variables
r_max = bilevel.addVar(lb= 0 , ub= gp.GRB.INFINITY, vtype=gp.GRB.CONTINUOUS, name="r_max")

 

x_ij_km = {}
for i, j in edges:
    for k in K:
        for m in M:
            x_ij_km[i, j, k, m] = bilevel.addVar(lb=0, ub=gp.GRB.INFINITY, vtype=gp.GRB.CONTINUOUS, name=f"x_{i}_{j}_{k}_{m}")

When I run the following constraint (
bilevel.addConstrs(sum(x_ij_km[i, j, k, m] * l_ij_mk_c[i, j, k, m, c] * l_ij_mk_c * phi_k[k] for k in K for m in M for i,j in edges) <= r_max for c in C) 

Note: l_ij_mk_c, l_ij_mk_c, phi_k are all parameters 
I receive the following error:

    bilevel.addConstrs(sum(x_ij_km[i, j, k, m] * l_ij_mk_c[i, j, k, m, c] * sigma_ij_km[i, j, k, m] * phi_k[k] for k in K for m in M for i,j in edges) <= r_max for c in C)

  File src/gurobipy/tempconstr.pxi:57 in gurobipy.TempConstr.__bool__

GurobiError: Constraint has no bool value (are you trying "lb <= expr <= ub"?)

What might be the reason? How can I fix that?

0

• 

  Marika Karbstein

  • Gurobi Staff

  January 26, 2024 10:44

  Please check the article Constraint has no bool value (are you trying "lb <= expr <= ub"?)  for a solution.

  If you do not find any, then please create a minimum reproducible example (Tutorial: Preparing a Minimal Reproducible Example).

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