VERSION

using JuMP
using Ipopt

m = Model(solver = IpoptSolver())
@variable(m, x, start = 0.0)
@variable(m, y, start = 0.0)

@NLobjective(m, Min, (1-x)^2 + 100(y-x^2)^2)

solve(m)
println("x = ", getvalue(x), " y = ", getvalue(y))

# adding a (linear) constraint
@constraint(m, x + y == 10)
solve(m)
println("x = ", getvalue(x), " y = ", getvalue(y))

using Ipopt

m = Model(solver=IpoptSolver())
@variable(m, 0 <= x <= 2 )
@variable(m, 0 <= y <= 30 )

@objective(m, Min, x*x+ 2x*y + y*y )
@constraint(m, x + y >= 1 )

print(m)

status = solve(m)

print(status)

println("x = ", getvalue(x), "and y = ", getvalue(y))