24.03.2013 Views

Iterative Methods for Sparse Linear Systems Second Edition

Iterative Methods for Sparse Linear Systems Second Edition

Iterative Methods for Sparse Linear Systems Second Edition

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

13.4.3 V-cycles and W-cycles . . . . . . . . . . . . . . . 443<br />

13.4.4 Full Multigrid . . . . . . . . . . . . . . . . . . . 447<br />

13.5 Analysis <strong>for</strong> the two-grid cycle . . . . . . . . . . . . . . . . . 451<br />

13.5.1 Two important subspaces . . . . . . . . . . . . . 451<br />

13.5.2 Convergence analysis . . . . . . . . . . . . . . . 453<br />

13.6 Algebraic Multigrid . . . . . . . . . . . . . . . . . . . . . . . 455<br />

13.6.1 Smoothness in AMG . . . . . . . . . . . . . . . . 456<br />

13.6.2 Interpolation in AMG . . . . . . . . . . . . . . . 457<br />

13.6.3 Defining coarse spaces in AMG . . . . . . . . . . 460<br />

13.6.4 AMG via Multilevel ILU . . . . . . . . . . . . . 461<br />

13.7 Multigrid vs Krylov methods . . . . . . . . . . . . . . . . . . 464<br />

14 Domain Decomposition <strong>Methods</strong> 469<br />

14.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 469<br />

14.1.1 Notation . . . . . . . . . . . . . . . . . . . . . . 470<br />

14.1.2 Types of Partitionings . . . . . . . . . . . . . . . 472<br />

14.1.3 Types of Techniques . . . . . . . . . . . . . . . . 472<br />

14.2 Direct Solution and the Schur Complement . . . . . . . . . . . 474<br />

14.2.1 Block Gaussian Elimination . . . . . . . . . . . . 474<br />

14.2.2 Properties of the Schur Complement . . . . . . . 475<br />

14.2.3 Schur Complement <strong>for</strong> Vertex-Based Partitionings 476<br />

14.2.4 Schur Complement <strong>for</strong> Finite-Element Partitionings 479<br />

14.2.5 Schur Complement <strong>for</strong> the model problem . . . . 481<br />

14.3 Schwarz Alternating Procedures . . . . . . . . . . . . . . . . . 484<br />

14.3.1 Multiplicative Schwarz Procedure . . . . . . . . . 484<br />

14.3.2 Multiplicative Schwarz Preconditioning . . . . . . 489<br />

14.3.3 Additive Schwarz Procedure . . . . . . . . . . . . 491<br />

14.3.4 Convergence . . . . . . . . . . . . . . . . . . . . 492<br />

14.4 Schur Complement Approaches . . . . . . . . . . . . . . . . . 497<br />

14.4.1 Induced Preconditioners . . . . . . . . . . . . . . 497<br />

14.4.2 Probing . . . . . . . . . . . . . . . . . . . . . . . 500<br />

14.4.3 Preconditioning Vertex-Based Schur Complements 500<br />

14.5 Full Matrix <strong>Methods</strong> . . . . . . . . . . . . . . . . . . . . . . . 501<br />

14.6 Graph Partitioning . . . . . . . . . . . . . . . . . . . . . . . . 504<br />

14.6.1 Basic Definitions . . . . . . . . . . . . . . . . . . 504<br />

14.6.2 Geometric Approach . . . . . . . . . . . . . . . . 505<br />

14.6.3 Spectral Techniques . . . . . . . . . . . . . . . . 506<br />

14.6.4 Graph Theory Techniques . . . . . . . . . . . . . 507<br />

References 514<br />

Index 535

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!