This project examines a number of problems associated with interior point methods for linear programming. It begins with the observation that under certain conditions the affine scalding algorithm converges at a superlinear rate when applied to the feasibility problem. Then every linear programming problem is approximated by a feasibility problem. The main technical difficulties have to do with degeneracies in linear programming problems. With assumptions about problems being nondegenerate results about superlinear convergence are proved, but superlinear convergence has been observed even in degenerate cases. So what is actually required for superlinear convergence is not clear. Trying to accelerate affine scaling algorithms leads naturally to questions about centers of polytopes. The existence of a large set of "centers" inside every polytope, except these equivalent to simplicies is shown. The affine scaling algorithm converges fast when started at one of these general centers. To discover means of computing centers efficiently is a goal of this research. After finding ways of accelerating convergence, the questions of how to perform each step efficiently is addressed. The least square problems will be solved by a preconditioned conjugate gradient algorithm.

Project Start
Project End
Budget Start
1991-03-01
Budget End
1994-02-28
Support Year
Fiscal Year
1990
Total Cost
$198,174
Indirect Cost
Name
Georgia Tech Research Corporation
Department
Type
DUNS #
City
Atlanta
State
GA
Country
United States
Zip Code
30332