**Pat Keast** was Scottish mathematician who specialised in numerical analysis.

- His parents were John Keast (born in Broxburn in 1913), a bus driver, and Rose Gorman (born in Broxburn in 1918).
- In October 1960, Keast began his studies at the University of Edinburgh taking courses in mathematics, physics and chemistry.
- It was Jim Fulton's honours course on numerical analysis which was particularly influential in inspiring Keast to become a numerical analyst.
- At Edinburgh University, Keast was in a class which contained a number of students who went on to academic careers including Colin Campbell, whose career was at the University of St Andrews, and Alistair Watson, whose career was at Dundee University.
- Keast was one of the best of these First Class students.
- After graduating with his first degree, in 1964 Keast was appointed as an Assistant Lecturer in Mathematics at the University of St Andrews.
- Graeme Fairweather, who graduated with a First Class Honours degree from St Andrews in 1963, was another of Mitchell's students at this time and he became a close friend of Keast.
- In 1966 Keast, in collaboration with his thesis advisor Ron Mitchell, published the paper On the instability of the Crank Nicolson formula under derivative boundary conditions.
- Keast also worked with Edward Copson who was the Regius Professor of Mathematics at St Andrews.
- In the following year, 1967, Keast published his second paper with Ron Mitchell, Finite difference solution of the third boundary problem in elliptic and parabolic equations.
- In 1967 Keast was awarded a Ph.D. for his thesis on numerical analysis and he was promoted to lecturer.
- Colin Campbell, who had been in the same class as Keast as an undergraduate at Edinburgh, had spent 1964-65 studying for a Master's degree at McGill in Canada before being appointed to St Andrews in 1965.
- He and Keast wrote the joint paper The stability of difference approximations to a selfadjoint parabolic equation, under derivative boundary conditions which was published in 1968.
- Keast was a keen sportsman and an enthusiastic cyclist taking part in competitive events.
- Keast's first single author paper was The third boundary value problem for elliptic equations (1968).
- In 1968-69 Keast made his first visit to Canada when he was a Visiting Assistant Professor at the University of Toronto.
- While in Toronto, we met up with Pat Keast who invited us to an excellent meal at the University of Toronto staff club.
- Keast moved to Halifax, Canada, in 1983 when he was appointed as a full professor in the division of Computing Science of Dalhousie University, at that time a newly established division within the Mathematics Department.
- Keast was a main organiser of the Workshop which was attended by thirty-six scientists from eleven NATO countries.
- Thirteen invited lectures and twenty-two contributed lectures were presented and a volume, jointly edited by Patrick Keast and Graeme Fairweather, was produced containing twenty-five articles based on the lectures given at the workshop.
- When the division of Computing Science split from the Mathematics Department to become a department of its own, Keast became a member of the Mathematics Department.
- On 1 July 2003, Keast became Chairman of the Mathematics Department taking over from Richard Nowakowski.
- Keast had many other roles in the Dalhousie Mathematics Department including Mathematics Graduate Coordinator and an organiser of the Annual Bluenose Numerical Analysis Day until 2009.
- The 2008 meeting took place at Dalhousie on 13 June with Keast as the local organiser.
- As a lecturer, Keast was much appreciated by his students.
- In 2007 Keast retired although he continued to undertake work for the Department.
- We must mention Keast's work for the Church, particularly in the communities of St Pius X and St Benedict's and through his support for the poor in working for the St Vincent de Paul Society.
- Let us record two tributes paid to Keast after his death.
- He'll always be Dr Keast to me.

Born 2 August 1942, Broxburn, West Lothian, Scotland. Died 25 July 2016, Halifax, Nova Scotia, Canada.

View full biography at MacTutor

Origin Scotland

**Oâ€™Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive