John G.F. Francis
Encyclopedia
John G.F. Francis is an English computer scientist
, who in 1961 published the QR algorithm
for computing the eigenvalues and eigenvectors of matrices, which has been named as one of the ten most important algorithm
s of the twentieth century. The algorithm was also proposed independently by Vera N. Kublanovskaya of the Soviet Union
in the same year.
Born in London
in 1934, Francis presently resides in Hove
, England
(near Brighton
). In 1954 he worked for the National Research Development Corporation
(NRDC). In 1955–1956 he attended Cambridge University, but did not complete a degree. He then returned to the NRDC, where he served as assistant to Christopher Strachey
. At this time he devised the QR transformation. In 1961 he left the NRDC to work at Ferranti Corporation, Ltd. and then at the University of Sussex
. Subsequently, he had positions with various industrial organizations and consultancies. His interests encompassed artificial intelligence
, computer languages, and systems engineering
, although he never returned to the field of numerical computation. He is currently retired.
By 1962, Francis had left the field of numerical analysis
, and subsequently had no idea of the impact his work on the QR algorithm had had, until re-contacted by Gene Golub and Frank Uhlig in 2007. Still in good health, he was the opening speaker at a mini-symposium that marked 50 years of the QR algorithm, held at the 23rd Biennial Conference on Numerical Analysis, in Glasgow, in June 2009.
Computer scientist
A computer scientist is a scientist who has acquired knowledge of computer science, the study of the theoretical foundations of information and computation and their application in computer systems....
, who in 1961 published the QR algorithm
QR algorithm
In numerical linear algebra, the QR algorithm is an eigenvalue algorithm: that is, a procedure to calculate the eigenvalues and eigenvectors of a matrix. The QR transformation was developed in the late 1950s by John G.F. Francis and by Vera N. Kublanovskaya , working independently...
for computing the eigenvalues and eigenvectors of matrices, which has been named as one of the ten most important algorithm
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...
s of the twentieth century. The algorithm was also proposed independently by Vera N. Kublanovskaya of the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
in the same year.
Born in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
in 1934, Francis presently resides in Hove
Hove
Hove is a town on the south coast of England, immediately to the west of its larger neighbour Brighton, with which it forms the unitary authority Brighton and Hove. It forms a single conurbation together with Brighton and some smaller towns and villages running along the coast...
, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
(near Brighton
Brighton
Brighton is the major part of the city of Brighton and Hove in East Sussex, England on the south coast of Great Britain...
). In 1954 he worked for the National Research Development Corporation
National Research Development Corporation
The National Research Development Corporation was a non-departmental government body established by the British Government to transfer technology from the public sector to the private sector.-History:...
(NRDC). In 1955–1956 he attended Cambridge University, but did not complete a degree. He then returned to the NRDC, where he served as assistant to Christopher Strachey
Christopher Strachey
Christopher Strachey was a British computer scientist. He was one of the founders of denotational semantics, and a pioneer in programming language design...
. At this time he devised the QR transformation. In 1961 he left the NRDC to work at Ferranti Corporation, Ltd. and then at the University of Sussex
University of Sussex
The University of Sussex is an English public research university situated next to the East Sussex village of Falmer, within the city of Brighton and Hove. The University received its Royal Charter in August 1961....
. Subsequently, he had positions with various industrial organizations and consultancies. His interests encompassed artificial intelligence
Artificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
, computer languages, and systems engineering
Systems engineering
Systems engineering is an interdisciplinary field of engineering that focuses on how complex engineering projects should be designed and managed over the life cycle of the project. Issues such as logistics, the coordination of different teams, and automatic control of machinery become more...
, although he never returned to the field of numerical computation. He is currently retired.
By 1962, Francis had left the field of numerical analysis
Numerical analysis
Numerical analysis is the study of algorithms that use numerical approximation for the problems of mathematical analysis ....
, and subsequently had no idea of the impact his work on the QR algorithm had had, until re-contacted by Gene Golub and Frank Uhlig in 2007. Still in good health, he was the opening speaker at a mini-symposium that marked 50 years of the QR algorithm, held at the 23rd Biennial Conference on Numerical Analysis, in Glasgow, in June 2009.
Further reading
- Gene Golub, Frank Uhlig (2009), "The QR algorithm: 50 years later – its genesis by John Francis and Vera Kublanovskaya, and subsequent developments", IMA Journal of Numerical Analysis, vol. 29, no. 3, pages 467-485.advanced publication online