Something strange happens with my program.
using JuMP, Ipopt, CPLEX, Juniper
m = Model(solver=juniper)
@variable(m, x, start = 0.0)
@variable(m, y, start = 0.0)
@NLobjective(m, Min, sin((1-5x))^2 + 100(cos(y-x^2))^2)
println("x = ", getvalue(x), " y = ", getvalue(y))
where, I set the initial guess to x = 0 and y = 0. The solution provided is
x = 0.828318530664551 y = -0.8846847385581247
I want to resolve this MINLP and change the starting point to optimize. However, when I change the starting point, the optimal solution obtained is the same. This not happen.
Can anybody help me or give a advise how can I set the initial guess in MINLP?