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240CHAPTER 12. RAYLEIGH QUOTIENT AND TRACE MINIMIZATION

2.Multiple dynamic shifts. Each linear system (12.57) is solved with an individual shift. The shift is ‘turned on’ close to convergence. Since the linear systems are indefinite, PCG has to be adapted.

3.Preconditioning. The linear systems (12.57) can be preconditioned, e.g., by a matrix of the form M = CC where CC ≈ A is an incomplete Cholesky factorization. One then solves

(12.57)

P˜(A˜ − σi(k)M˜ )P˜d˜i(k) = P˜˜ri, X˜k M˜ d˜i(k) = 0

˜ −1 − ˜ −1 − ˜(k)

with A = C AC , M = C MC , di

˜ − ˜ ˜ ˜ ˜ 2 ˜ −1 ˜ ˜ and P = I MXk(Xk M Xk) Xk M.

(k) ˜ (k) (k)

= C di , Xk = C Xk, x˜i = C xi ,

In Table 12.2 results are collected for some problems in the Harwell-Boeing collection [10]. These problems are di cult because the gap ratios for the smallest eigenvalues are extremely small due to the huge span of the spectra. Without preconditioning, none of these problems can be solved with a reasonable cost. In the experiments, the incomplete Cholesky factorization (IC(0)) of A was used as the preconditioner for all the matrices of the form A − σB.

Problem

Size

Max #

Block Jacobi-Davidson

Davidson-type tracemin

 

 

inner its

#its

A mults

time[sec]

#its

A mults

time[sec]

 

 

 

 

 

 

 

 

 

BCSST08

1074

40

34

3954

4.7

10

759

0.8

BCSST09

1083

40

15

1951

2.2

15

1947

2.2

BCSST11

1473

100

90

30990

40.5

54

20166

22.4

BCSST21

3600

100

40

10712

35.1

39

11220

36.2

BCSST26

1922

100

60

21915

32.2

39

14102

19.6

Table 12.2: Numerical results for problems from the HarwellBoeing collection with four processors

The Davidson-type trace minimization algorithm with multiple dynamic shifts works better than the block Jacobi–Davidson algorithm for three of the five problems. For the other two, the performance for both algorithms is similar.

Bibliography

[1]P. ARBENZ, U. L. HETMANIUK, R. B. LEHOUCQ, AND R. TUMINARO, A comparison

of eigensolvers for large-scale 3D modal analysis using AMG-preconditioned iterative methods, Internat. J. Numer. Methods Eng., 64 (2005), pp. 204–236.

[2]O. AXELSSON AND V. BARKER, Finite Element Solution of Boundary Value Problems, Academic Press, Orlando FL, 1984.

[3]D. K. FADDEEV AND V. N. FADDEEVA, Computational Methods of Linear Algebra, Freeman, San Francisco, 1963.

[4]Y. T. FENG AND D. R. J. OWEN, Conjugate gradient methods for solving the smallest eigenpair of large symmetric eigenvalue problems, Internat. J. Numer. Methods Eng., 39 (1996), pp. 2209–2229.

BIBLIOGRAPHY

241

[5]M. R. HESTENES AND E. STIEFEL, Methods of conjugent gradients for solving linear systems, J. Res. Nat. Bur. Standards, 49 (1952), pp. 409–436.

[6]A. V. KNYAZEV, Toward the optimal preconditioned eigensolver: Locally optimal block preconditioned conjugate gradient method, SIAM J. Sci. Comput., 23 (2001), pp. 517–541.

[7]A. V. KNYAZEV, M. E. ARGENTATI, I. LASHUK, AND E. E. OVTCHINNIKOV, Block

locally optimal preconditioned eigenvalue Xolvers (BLOPEX) in hypre and PETSc, SIAM J. Sci. Comput., 29 (2007), pp. 2224–2239.

[8]D. E. LONGSINE AND S. F. MCCORMICK, Simultaneous Rayleigh–quotient minimization methods for Ax = λBx, Linear Algebra Appl., 34 (1980), pp. 195–234.

[9]A. RUHE, Computation of eigenvalues and vectors, in Sparse Matrix Techniques, V. A. Barker, ed., Lecture Notes in Mathematics 572, Berlin, 1977, Springer, pp. 130–184.

[10]A. SAMEH AND Z. TONG, The trace minimization method for the symmetric generalized eigenvalue problem, J. Comput. Appl. Math., 123 (2000), pp. 155–175.

[11]A. H. SAMEH AND J. A. WISNIEWSKI, A trace minimization algorithm for the generalized eigenvalue problem, SIAM J. Numer. Anal., 19 (1982), pp. 1243–1259.

[12]H. R. SCHWARZ, Rayleigh–Quotient–Minimierung mit Vorkonditionierung, in Numerical Methods of Approximation Theory, Vol. 8, L. Collatz, G. Meinardus, and G. N¨urnberger, eds., vol. 81 of International Series of Numerical Mathematics (ISNM), Basel, 1987, Birkh¨auser, pp. 229–45.

[13]G. L. G. SLEIJPEN AND H. A. VAN DER VORST, Jacobi–Davidson method, in Templates for the solution of Algebraic Eigenvalue Problems: A Practical Guide, Z. Bai, J. Demmel, J. Dongarra, A. Ruhe, and H. van der Vorst, eds., SIAM, Philadelphia, PA, 2000, pp. 238–246.

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