I am using Ipopt to solve the non linear optimization problem. My code is running but gives an error when the final solution is to be dispalyed as " An object of name x is already attached to this model. If this is intended, consider using the anonymous construction syntax. " How do I solve this please?
My code is below
using JuMP
import Juniper
import Ipopt
NumVar = 5
a = [46.891299081399524, 18.358839924481327, 24.81156595151281, 14.307918586681046, 45.809245326064875] # x-cordinates of selected circle
b = [34.20824038054229, 34.209275827684294, 15.03051769314379, 5.0321444549166845, 17.229495614433407] # y-cordinates of selected circle
r = [20, 20, 20, 20, 20 ] # Radius of selected circles
R = 0.0
model = Model(
optimizer_with_attributes(
Juniper.Optimizer,
"nl_solver" => optimizer_with_attributes(
Ipopt.Optimizer,
MOI.Silent() => true,
),
),
)
function inner_loop(x, y,R)
for i in 1:length(a)
R = max(R, sqrt((a[i] - x)^2 + (b[i] - y)^2) + r[i])
end
#model = Model(Mosek.Optimizer)
@variable(model, x >= 0)
@variable(model, y >= 0)
@variable(model, z >= 0)
@NLobjective(model, Min, x^2 + y^2 - z)
@NLconstraint(
model,
[i in 1:NumVar],
-2 * x * a[i] - 2 * b[i] * y + z <= (R - r[i])^2 - a[i]^2 - b[i]^2, )
@show model
print(model)
optimize!(model)
return value(x), value(y), value(z), value(R)
end
function main()
x, y, z, R = 0.0, 0.0, Inf, 0.0
while abs(x^2 + y^2 - z) >= 0.01
x, y, z, R = inner_loop(x, y,R,)
end
print("The abs value is: abs(x^2+y^2-z) = " , abs(x^2+y^2-z))
return x, y, z, R
end
main()