William B. Gragg

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William B. Gragg
Born(1936-11-02)2 November 1936
Died25 December 2016(2016-12-25) (aged 80)
NationalityAmerican
Alma materUCLA
Known forGragg Extrapolation
Scientific career
FieldsMathematics
InstitutionsNaval Postgraduate School
Thesis Repeated extrapolation to the limit in the numerical solution of ordinary differential equations  (1964)
Doctoral advisorPeter Henrici

William B. Gragg (1936–2016) ended his career as an emeritus professor in the Department of Applied Mathematics at the Naval Postgraduate School. He has made fundamental contributions in numerical analysis, particularly the areas of numerical linear algebra and numerical methods for ordinary differential equations.

He received his PhD at UCLA in 1964 under the direction of Peter Henrici. His dissertation work resulted in the Gragg Extrapolation method[1] for the numerical solution of ordinary differential equations (sometimes also called the Bulirsch–Stoer algorithm).

Gragg is also well known for his work on the QR algorithm for unitary Hessenberg matrices, on updating the QR factorization,[2] superfast solution of Toeplitz systems,[3] parallel algorithms for solving eigenvalue problems,[4][5] as well as his exposition on the Pade table and its relation to a large number of algorithms in numerical analysis.[6]

References[edit]

  1. ^ http://epubs.siam.org/doi/pdf/10.1137/0702030 On extrapolation algorithms for ordinary initial value problems, WB Gragg SINUM, vol. 2, no. 3, 1965.
  2. ^ Daniel, J. W.; Gragg, W. B.; Kaufman, L.; Stewart, G. W. (1976). "Reorthogonalization and stable algorithms for updating the Gram-Schmidt factorization". Math. Comp. 30 (136): 772–795. doi:10.1090/S0025-5718-1976-0431641-8.
  3. ^ Ammar, Gregory S.; Gragg, William B. (1988). "Superfast Solution of Real Positive Definite Toeplitz Systems". SIAM Journal on Matrix Analysis and Applications. 9: 61–76. CiteSeerX 10.1.1.64.8032. doi:10.1137/0609005. hdl:10945/30445.
  4. ^ Article title A Parallel Divide and Conquer Algorithm for the Generalized Real Symmetric Definite Tridiagonal Eigenproblem, C.F. Borges and W.B.Gragg, 1992
  5. ^ Gragg, W. B.; Reichel, L. (1990). "A divide and conquer method for unitary and orthogonal eigenproblems". Numerische Mathematik. 57: 695–718. doi:10.1007/BF01386438. hdl:10945/29823. S2CID 53684596.
  6. ^ Gragg, W. B. (1972). "The Padé Table and Its Relation to Certain Algorithms of Numerical Analysis". SIAM Review. 14: 1–62. doi:10.1137/1014001.

External links[edit]