Solving Some Large Scale Semidefinite Programs via the Conjugate Residual Method

  • Authors:
  • Kim-Chuan Toh;Masakazu Kojima

  • Affiliations:
  • -;-

  • Venue:
  • SIAM Journal on Optimization
  • Year:
  • 2002

Quantified Score

Hi-index 0.00

Visualization

Abstract

Most current implementations of interior-point methods for semidefinite programming use a direct method to solve the Schur complement equation (SCE) $M \Delta y=h$ in computing the search direction. When the number of constraints is large, the problem of having insufficient memory to store M can be avoided if an iterative method is used instead. Numerical experiments have shown that the conjugate residual (CR) method typically takes a huge number of steps to generate a high accuracy solution. On the other hand, it is difficult to incorporate traditional preconditioners into the SCE, except for block diagonal preconditioners. We decompose the SCE into a 2 × 2 block system by decomposing $\Delta y$ (similarly for h) into two orthogonal components with one lying in a certain subspace that is determined from the structure of M. Numerical experiments on semidefinite programming problems arising from the Lovász $\theta$-function of graphs and MAXCUT problems show that high accuracy solutions can be obtained with a moderate number of CR steps using the proposed equation.