I got the idea for these test matrices from Gene Golub years ago, but the mathematical foundation comes from a paper by Divakar Viswanath and Nick Trefethen. ... read more >>

I have just returned from two meetings in Europe, the 26th Biennial Conference on Numerical Analysis at the University of Strathclyde in Glasgow, Scotland, and Sparse Days III in Saint-Girons, France.... read more >>

Augustin (Austin) Dubrulle deserves to be better known in the numerical linear algebra community. His version of the implicit QR algorithm for computing the eigenvalues of a symmetric tridiagonal matrix that was published in a half-page paper in Numerische Mathematik in 1970 is faster than Wilkinson's version published earlier. It is still a core algorithm in MATLAB today. ... read more >>

The 1960 programming language ALGOL 60 influenced the design of many subsequent languages, including C and a miniature language called PL/0. I based the design of the first MATLAB on PL/0.... read more >>

Fritz Bauer, eminent German computer scientist and last surviving member of the organizing committee of the 1964 Gatlingburg Conference on Numerical Algebra, passed away on March 26 at the age of 90.... read more >>

Single and double precision are combined to facilitate a triple precision accumulated inner product.... read more >>

Iterative refinement is a technique introduced by Wilkinson for reducing the roundoff error produced during the solution of simultaneous linear equations. Higher precision arithmetic is required for the calculation of the residuals.... read more >>

The Method of Particular Solutions computes a highly accurate approximation to the eigenvalue we have been seeking, and guaranteed bounds on the accuracy. It also provides flexibility involving the boundary conditions that leads to the MathWorks logo. ... read more >>

The Partial Differential Equation Toolbox contains tools for the analysis of PDEs in two space dimensions and time. It is perhaps not surprising that one of the primary examples involves the L-shaped membrane.... read more >>

This is the third in a series of posts on the finite Fourier transform. The Fourier matrix produces an interesting graphic and has a surprising eigenvalue distribution. ... read more >>