Multicolor reordering of sparse matrices resulting from irregular grids

  • Authors:
  • Rami G. Melhem;K. V. S. Ramarao

  • Affiliations:
  • Department of Computer Science, The University of Pittsburgh, Pittsburgh, PA;Department of Computer Science, The University of Pittsburgh, Pittsburgh, PA

  • Venue:
  • ACM Transactions on Mathematical Software (TOMS)
  • Year:
  • 1988

Quantified Score

Hi-index 0.00

Visualization

Abstract

Many iterative algorithms for the solution of large linear systems may be effectively vectorized if the diagonal of the matrix is surrounded by a large band of zeroes, whose width is called the zero stretch. In this paper, a multicolor numbering technique is suggested for maximizing the zero stretch of irregularly sparse matrices. The technique, which is a generalization of a known multicoloring algorithm for regularly sparse matrices, executes in linear time, and produces a zero stretch approximately equal to n/2&sgr;, where 2&sgr; is the number of colors used in the algorithm. For triangular meshes, it is shown that &sgr; ≤ 3, and that it is possible to obtain &sgr; = 2 by applying a simple backtracking scheme.