The legacy INTPOINT procedure solves the network program with side constraints (NPSC) problem and the more general linear programming (LP) problem using a primal-dual predictor-corrector interior point algorithm. While many of the problems might best be formulated as LP problems, there might be other instances when they are better formulated as NPSC problems. After it reads the NPSC data, PROC INTPOINT converts the problem into an equivalent LP problem, performs interior point optimization, then converts the solution it finds back into a form that can be used as the optimum to the original NPSC model.
To solve LP problems using PROC INTPOINT, you save a representation of the LP variables and the constraints in one or two SAS data sets. These data sets are then passed to PROC INTPOINT for solution. To solve NPSC problems using PROC INTPOINT, you save a representation of the network and the side constraints in three SAS data sets. These data sets are then passed to PROC INTPOINT for solution. A problemís data can take various forms; you can use any one, or a combination, of several of these forms.