Charles William Clenshaw
Charles William Clenshaw (15 March 1926, Southend-on-Sea, Essex – 23 September 2004) was an English mathematician, specializing in numerical analysis. He is known for the Clenshaw algorithm (1955) and Clenshaw–Curtis quadrature (1960). In a 1984 paper Beyond Floating Point, Clenshaw and Frank W. J. Olver introduced symmetric level-index arithmetic.