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Effective condition number and its applications

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Abstract

Consider the over-determined system Fx = b where \({{\bf F}\in\mathcal{R}^{m \times n}, m \geq n}\) and rank (F) = rn, the effective condition number is defined by \({{\rm Cond_{-}eff }= \frac {\|{\bf b}\|}{\sigma_r\|{\bf x}\|}}\), where the singular values of F are given as σ max = σ 1σ 2 ≥ . . . ≥ σ r > 0 and σ r+1 = . . . = σ n = 0. For the general perturbed system (AA)(xx) = bb involving both ΔA and Δb, the new error bounds pertinent to Cond_eff are derived. Next, we apply the effective condition number to the solutions of Motz’s problem by the collocation Trefftz methods (CTM). Motz’s problem is the benchmark of singularity problems. We choose the general particular solutions \({v_L = \sum\nolimits_{k=0}^L d_k (\frac {r}{R_p})^{k+\frac 12}}\) \({{\rm cos}(k +\frac 12)\theta}\) with a radius parameter R p . The CTM is used to seek the coefficients d i by satisfying the boundary conditions only. Based on the new effective condition number, the optimal parameter R p = 1 is found. which is completely in accordance with the numerical results. However, if based on the traditional condition number Cond, the optimal choice of R p is misleading. Under the optimal choice R p = 1, the Cond grows exponentially as L increases, but Cond_eff is only linear. The smaller effective condition number explains well the very accurate solutions obtained. The error analysis in [14,15] and the stability analysis in this paper grant the CTM to become the most efficient and competent boundary method.

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References

  1. Atkinson KE (1989) An Introduction to Numerical Analysis, 2nd edn. Wiley, New York

    MATH  Google Scholar 

  2. Babuska I, Aziz AK (1973) Survey lectures in the mathematical foundations of the finite elements. In: Aziz AK (ed) The mathematical foundation of the finite element methods with applications to partial differential equations. Academic Press, New York and London, pp 3–369

    Google Scholar 

  3. Chan TF, Foulser DE (1988) Effectively well-conditioned linear systems. SIAM J Stat Comput 9: 963–969

    Article  MATH  MathSciNet  Google Scholar 

  4. Christiansen S, Hansen PC (1994) The effective condition number applied to error analysis of certain boundary collocation methods. J Comput Appl Math 54: 15–36

    Article  MATH  MathSciNet  Google Scholar 

  5. Diao H, Wei Y (2007) On Frobenius normwise condition numbers for Moore-Penrose inverse and linear least-squares problems. Numer Linear Algebra Appl 14: 603–610

    Article  MATH  MathSciNet  Google Scholar 

  6. Golub GH, van Loan CF (1989) Matrix computations, 2nd edn. The Johns Hopkins, Baltimore and London

    MATH  Google Scholar 

  7. Higam N (2002) Accuracy and stabiltiy of numerical algorithms, 2nd edn. SIAM, Philadelphia

    Google Scholar 

  8. Horn RA, Johnson CR (1990) Matrix analysis. Cambridge University Press, Cambridge and London

    MATH  Google Scholar 

  9. Kite E, Kamiya N (1995) Trefftz method: an overview. Adv Eng Softw 24: 3–12

    Article  Google Scholar 

  10. Li ZC (1998) Combined methods for elliptic equations with singularities, interfaces and infinities. Kluwer, Dordrecht

    MATH  Google Scholar 

  11. Li ZC, Chien CS, Huang HT (2007) Effective condition number for Finite difference method. J Comput Appl Math 198: 208–235

    Article  MATH  MathSciNet  Google Scholar 

  12. Li ZC, Huang HT (2008) Effective condition number for numerical partial differential equations. Numer Linear Algebra Appl 15: 575–594

    Article  MathSciNet  Google Scholar 

  13. Li ZC, Mathon R, Sermer P (1987) Boundary methods for solving elliptic problem with singularities and interfaces. SIAM J Numer Anal 24: 487–498

    Article  MATH  MathSciNet  Google Scholar 

  14. Li ZC, Lu TT, Huang HT, Cheng AH-D (2007) Trefftz, collocation and other boundary methods: a comparison. Numer Methods PDE 23: 93–144

    Article  MATH  MathSciNet  Google Scholar 

  15. Li ZC, Lu TT, Hu HY, Cheng AH-D (2008) Trefftz and collocation methods. WIT Publisher, Southsampton

    MATH  Google Scholar 

  16. Lu TT, Hu HY, Li ZC (2004) Highly accurate solutions of Motz’s and the cracked beam problems. Eng Anal Bound Elem 28: 1387–1403

    Article  MATH  Google Scholar 

  17. Liu CS (2007) A highly accurate solver for the mixed-boundary potential problem and singular problem in arbitrary plane domain. CMES 20(2): 111–122

    MathSciNet  Google Scholar 

  18. Liu CS (2007) A modified Trefftz method for two-dimensional Laplace equation considering the domain characteristic length. CMES 21(1): 53–65

    MathSciNet  Google Scholar 

  19. Oden JT, Reddy JN (1976) An introduction to the mathematical theory of finite elements. Wiley, New York

    MATH  Google Scholar 

  20. Rice JR (1981) Matrix computations and mathematical software. McGraw-Hill Book Company, New York

    MATH  Google Scholar 

  21. Rosser JB, Paramichael N (1975) A power series solution of a harmonic mixed boundary value problem, MRC, Technical report, University of Wisconsin

  22. Stewart GW (1977) On the perturbation od pseudo-inverse, projections and linear least squares problems. SIAM Rev 19: 634–662

    Article  MATH  MathSciNet  Google Scholar 

  23. Stewart G (1998) Matrix algorithms i: basic decompositions. SIAM, Philadelphia

    MATH  Google Scholar 

  24. Sun JG (2001) Perturbation analysis of matrix (in Chinese), 2nd edn. Science Press, Beijing

    Google Scholar 

  25. Van Loan CF (1976) Generating the singular value decomposition. SIAM J Numer Anal 13: 76–83

    Article  MATH  MathSciNet  Google Scholar 

  26. Wang G, Wei Y, Qiao S (2004) Generalized inverses: theory and computations. Science Press, Beijing

    Google Scholar 

  27. Wedin PÅ (1973) Perturbation theory for pseudo-inverses. BIT 13: 217–232

    Article  MATH  MathSciNet  Google Scholar 

  28. Wilkinson JH (1965) The algebraic Eigenvalue problem. Clarendon Press, Oxford, p 191

    MATH  Google Scholar 

Download references

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Correspondence to Yimin Wei.

Additional information

Communicated by N. Yan.

Partial results of this paper were represented at the Mini symposium on Collocation and Trefftz Method for the 7th World Congress on Computational Mechanics, Los Angeles, California, July 16–22, 2006.

Y. Wei was supported by the National Natural Science Foundation of China under grant 10871051, Doctoral Program of the Ministry of Education under grant 20090071110003, Shanghai Science and Technology Committee under grant 08511501703, Shanghai Municipal Education Committee (Dawn Project) and 973 Program Project (No. 2010CB327900).

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Li, ZC., Huang, HT., Chen, JT. et al. Effective condition number and its applications. Computing 89, 87–112 (2010). https://doi.org/10.1007/s00607-010-0098-8

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  • DOI: https://doi.org/10.1007/s00607-010-0098-8

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