Author Archives: Nick Higham

The Strange Case of the Determinant of a Matrix of 1s and -1s

By Nick Higham and Alan Edelman (MIT) In a 2005 talk the second author noted that the MATLAB det function returns an odd integer for a certain 27-by-27 matrix composed of s and s: >> A = edelman; % Set … Continue reading

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Fun Books for Learning Programming

I learned Fortran from the TV course and book by Jeff Rohl. Some years later I came across A FORTRAN Coloring Book by Roger Emanuel Kaufman (MIT Press, 1978). The text is entirely handwritten (even the copyright page), is illustrated … Continue reading

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Org Mode Syntax Cheat Sheet

I’m a keen user of Emacs and Org mode for a variety of tasks, including note taking, generating documents for exporting to LaTeX, Word, or html. creating blog posts (notably for this blog, using Org2blog). Although Org mode is usually … Continue reading

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What’s New in MATLAB R2017b?

Following my earlier posts What’s New in MATLAB R2016b? and What’s New in MATLAB R2017a? I take a look here at the R2017b release of MATLAB. As before, this is not a comprehensive treatment (for which see the Release Notes), … Continue reading

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Foundations of Applied Mathematics Book Series

Foundations of Applied Mathematics, Volume 1: Mathematical Analysis was published by SIAM this summer. Written by Jeffrey Humpherys, Tyler J. Jarvis, and Emily J. Evans, all from Brigham Young University, this is the first of a four-book series, aimed at … Continue reading

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Christopher T. H. Baker (1939–2017)

By Nick Higham and Neville Ford (University of Chester) Christopher Thomas Hale Baker died on August 20, 2017 at the age of 78. He was born on the Isle of Thanet, Kent, in 1939, and was educated at Colchester Royal … Continue reading

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How Fast is Quadruple Precision Arithmetic?

When I am testing an algorithm running in double precision arithmetic I often want to compare the computed solution with a reference solution: a solution that is fully accurate to double precision. To obtain one I solve the same problem … Continue reading

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How and How Not to Compute a Relative Error

The relative error in a scalar as an approximation to a scalar is the absolute value of . I recently came across a program in which had been computed as . It had never occurred to me to compute it … Continue reading

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SIAM Annual Meeting 2017 Highlights

It’s a couple of weeks since the 2017 SIAM Annual Meeting, which I previewed in an earlier post. The meeting was held at the David Lawrence Convention Center in Pittsburgh and was co-chaired by Des Higham (University of Strathclyde) and … Continue reading

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Accelerating the Solution of Linear Systems by Iterative Refinement in Three Precisions

by Erin Carson and Nick Higham With the growing availability of half precision arithmetic in hardware and quadruple precision arithmetic in software, it is natural to ask whether we can harness these different precisions, along with the standard single and … Continue reading

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