cabs overloads absolute value using a nonlinear callback representation.


y = cabs(x)


The operator is used when you do not want the absolute value to be represented using an epigraph (in the convex case) or a MILP representation (in the nonconvex case) which you get if you use abs. Hence, a typical use is in a nonconvex case with a general nonlinear solver which does not have mixed-integer capabilities.