Edit1: Sorry i found lens next to avatar ^^
Hello
Please can I ask newbie q, i need to make signum variable from another variable.
(tried things like type Int in variable type / sign function in constrains but get errors from solver/constrains)
But i am failing even with 2 state (0,1) variable:
using JuMP
using Ipopt
model = Model()
@variable(model, d)
@objective(model, Max, d )
@constraint(model, d^2 == d)
set_optimizer(model, Ipopt.Optimizer)
optimize!(model)
value(d)
EXIT: Optimal Solution Found.
d=0.0
But d can be 1 :-/
How is possible to do sign like behavior?
Edit 2:
tried
model = Model()
@variable(model, d)
@variable(model, x)
@objective(model, Max, d )
@constraint(model, (x) == 4.65)
#@constraint(model, abs(x) == d*x)
@constraint(model, d*x == abs(x))
ERROR: MethodError: no method matching abs(::VariableRef)
Thanks