# James H. Wilkinson

James "Jim" Hardy " Wilkie " Wilkinson ( born September 27, 1919 in Strood, Kent, † October 5, 1986 in London) was a British mathematician who has enriched the numerical analysis, especially by working for backward analysis of rounding errors. 1970, the Turing Award has been awarded to him.

## Life

Wilkinson received at the age of eleven years, a scholarship to Sir Joseph Williamson 's Mathematical School and with 16 one for the Trinity College, University of Cambridge, where he met with 17 to study mathematics began (including when Abram Besikowitsch, Godfrey Hardy and John Littlewood ) and this 1939 at the age of 20 years left as valedictorian. During the Second World War he led for the British Ministry of Supply by means of numerical methods for ballistics calculations by. In 1945 he married Heather Nora Ware, with whom he had a daughter and a son. From 1946 to 1980 he worked at the National Physical Laboratory ( NPL) in Teddington, Middlesex. Starting in 1977, Wilkinson was at the same time (up to 1984) Professor at the Department of computer science at Stanford University in Palo Alto, California.

## Services

Alan Turing, who worked at the National Physical Laboratory from 1945 to 1948 also worked during this time the design of a computer, which was called following the Analytical Engine of Charles Babbage Automatic Computing Engine (ACE). Due to organizational problems at the NPL, the construction of the ACE delayed, however, which is why Alan Turing left the Institute. James Hardy Wilkinson, previously Turing's assistant, the team that finally transposed Turing's ideas and in 1950 a prototype of the ACE was finishing initiated. This prototype was the fastest computer in the world for some time. Responsible for the multiplication part of the calculator was developed by Wilkinson. From successor DEUCE more than 30 copies were produced, which were still partly in use until 1970.

Wilkinson became famous above all for his work on stability in numerical mathematics. Since computers work with floating point numbers limited accuracy, and rounding errors occur in calculations that can significantly distort the result. Wilkinson has worked intensively with the analysis of such rounding errors. Using the method he developed the backward analysis he proved fundamental results for error estimation, which are particularly important for the solution of linear systems of great importance. Together with Christian Reinsch published numerous Wilkinson developed and analyzed by the algorithms applied in the basic Handbook for Computation, Volume II, Linear Algebra was published in 1971 in the scientific publisher Springer. They have been implemented in software from 1971 by the Numerical Algorithms Group (NAG ). In addition, Wilkinson coined the term " sparse matrix ".

## Honors

For his achievements in numerical mathematics James Hardy Wilkinson in 1970 awarded the major Turing Award of the ACM. In the same year he was John von Neumann Lecturer of the Society for Industrial and Applied Mathematics. As early as 1963 he received an honorary doctorate from the University of Cambridge. In 1969 he was elected to the Royal Society of London. In 1977 he was made an honorary member of the British Institute of Mathematics and its Applications. In 1987 he received the Chauvenet Prize. He received an honorary doctorate from Brunel University, Heriot- Watt University, the University of Waterloo and the University of Essex.

The Argonne National Laboratory, the National Physical Laboratory and the Numerical Algorithms Group has been awarded since 1991 in four -year intervals, in his honor the JH Wilkinson Prize for Numerical Software and the SIAM will award the James H. Wilkinson Prize for Numerical Analysis and Scientific Computing.

In 1974 he was invited speaker at the International Congress of Mathematicians in Vancouver ( Invariant subspaces ), 1962 in Stockholm (Error bounds for unitary equivalence and similarity transformations ) and also in 1966 (A priori error estimates of algebraic processes ).

## Writings

- Rounding errors in algebraic processes. 1963 ( German rounding errors, translated by Gerhard Goos. 1969, Springer, Berlin, etc.)
- The Algebraic Eigenvalue Problem. 1965, Oxford University Press
- With Christian Reinsch: Handbook for Computation, Volume II, Linear Algebra, Springer -Verlag, 1971
- The Perfidious Polynomial. In: Studies in Numerical Analysis, pp. 1-28, MAA Stud Math 24, Math Assoc. America, Washington, DC, 1984