C. William Gear (Charles William "Bill" Gear; 1 February 1935, in London[1] – 15 March 2022, in Princeton, New Jersey[2]) was a British-American mathematician who specialized in numerical analysis and computer science.
in 1957 and a Ph.D. in 1960 under Abraham H. Taub with his thesis Singular Shock Intersections in Plane Flow.
Gear worked on numerical analysis, computer graphics, and software development.
He was known for the development of BDF methods (originally introduced by the chemists Charles Francis Curtiss and Joseph Oakland Hirschfelder in 1952), a multi-step method for solving stiff systems of differential equations.
Gear was elected as a member into the National Academy of Engineering in 1992 for seminal work in methods and software for solving classes of differential equations and differential-algebraic equations of significance in applications.