Add a Special Ordered Set (SOS) constraint to an lpSolve linear program model object.
add.SOS(lprec, name, type, priority, columns, weights)an lpSolve linear program model object.
a character string specifying a name for the SOS constraint.
a positive integer specifying the type of the SOS constraint.
an integer specifying the priority of the SOS constraint.
a numeric vector of unique values from the set {1, …, n} (where n is the number of decision variables in lprec) indicating which decision variables belong to the special ordered set.
a numeric vector the same length as columns specifying the variable weights.
If the operation was successful: a single integer value containing the list index of the new special ordered set. A return value of 0 indicates an error.