Charles William Clenshaw (15 March 1926, Southend-on-Sea, Essex – 23 September 2004)[1] was an English mathematician, specializing in numerical analysis.
In a 1984 paper Beyond Floating Point, Clenshaw and Frank W. J. Olver introduced symmetric level-index arithmetic.
There from 1961 to 1969 he was a senior principal scientific officer and headed the numerical methods group in NPL's mathematics division.
The mathematics department hosted the first four summer schools in numerical analysis sponsored by the UK's Engineering and Physical Sciences Research Council.
[1][3] Charles was head of Lancaster's mathematics department from 1975 to 1978 and from 1982 to 1984, but in the 1980s, the government instituted broad cuts in the number of faculty members in many universities.