History of Numerical Analysis


Oral Histories





C.W. (Bill) Gear

Oral History (pdf)

Interviewer: Thomas Haigh

Bill Gear discusses his entire career to date. Born in London in 1935, Gear studied mathematics at Cambridge before winning a fellowship for graduate study in America. He received a Ph.D. in mathematics from the University of Illinois, Urbana-Champaign in 1960, under the direction of Abraham Taub. During this time, Gear worked in the Digital Computer Laboratory, collaborating with Don Gillies on the design of ILLIAC II. He discusses in detail the operation of ILLIAC, its applications, and the work of the lab (including his relationships with fellow graduate student Gene Golub and visitor William Kahan). On graduation, Gear returned to England for two years, where he worked at IBM’s laboratory in Hursley on computer architecture projects, serving as a representative to the SPREAD committee charged with devising what became the System 360 architecture. Gear then returned to Urbana-Champaign, where he remained until 1990, serving as a professor of computer science and applied mathematics and, from 1985 onward, as head of the computer science department. Gear is best known for his work on the solution of stiff ordinary differential equations, and he discusses the origins of his interests in this area, the creation of his DIFSUB routine, and the impact of his book “Numerical Initial Value Problems in Ordinary Differential Equations” (1971). He also explores his work in other areas, including seminal contributions to the analysis of differential algebraic equations and work in the 1970s an ambitious system for generalized network simulation. Gear wrote several successful textbooks and was active in ACM’s SIGNUM and SIGRAPH, served as SIAM President and a member of the ACM Council as well as a number of blue ribbon panels and scholarly societies. In 1990 Gear left Illinois, to become one of the founding vice presidents of NEC’s new Research Institute in Princeton, New Jersey. From 1992 until his retirement in 2000, he was president of the institute, and he discusses his work there, the institute’s place within NEC, and its accomplishments and problems.

Key words: ILLIAC II, IBM System 360, stiff ordinary differential equations, mathematical software, DIFSUB, differential algebraic equations, network simulation, "Gear Anode"

Funding Agency: Atomic Energy Commission, U. S. Department of Energy

Time frame: 1960's, 1970's, 1980's, and 1990's

People: Don Gillies, Abraham Taub, Gene Golub, William (Velvel) Kahan, Arnold Nordsieck, Germund Dahlquist, Alan Hindmarsh, George Forsythe, Linda Petzold, Cleve Moler, Beresford Parlett

Location: Cambridge University, University of Illinois, Urbana-Champaign, IBM Hursley, Winchester, U.K., Argonne National Laboratory, Stanford University, NEC Research Institute, Princeton, Princeton University

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