I have spent much of my career working to bring abstract linear algebra and practical matrix computation closer together. This project is my latest effort.... 続きを読む >>

MATLAB has dozens of test matrices. Here are a few.... 続きを読む >>

(I have a guest blogger today. Ron Jones worked with me in 1985 for his Ph. D. from the University of New Mexico. He retired recently after nearly 40 years at Sandia National Labs in Albuquerque and now has a chance to return to the problem he studied in his thesis. -- CBM)... 続きを読む >>

I have just returned from a one-day workshop at U. C. Santa Barbara honoring John Gilbert on his 70th birthday and his official retirement after 20 years on the UCSB faculty.... 続きを読む >>

(The January 5 posting was premature and incomplete.)... 続きを読む >>

Christian Reinsch and Roland Bulirsch both passed away recently, Reinsch on October 8 and Bulirsch on September 21. Reinsch was 88 years old and Bulirsch was 89. Both of them were retired professors of numerical analysis at the Technical University of Munich. Both of them were friends of mine. But in almost all other ways, they were very different people.... 続きを読む >>

I do not recall having seen this matrix before, but I will not be surprised to learn that somebody else already knows all about it, especially if that person's name is Nick.... 続きを読む >>

The answer: A\A is always I, except when it isn't.... 続きを読む >>

In February and March I published three blog posts about an enhancement request for MATLAB concerning tie breakers with the round function, including the ability to round ties to even. Round One, Round Two and Round Three. Since then, a group of us at MathWorks, organized by my colleague (and academic great-great-grand-descendant) Heiko Weichelt, have been considering the request. We had a virtual design review recently. This post describes a prototype incorporating the features that were discussed at that review.... 続きを読む >>

I am giving a five-minute talk today, May 26, at the virtual seminar on Complexity of Matrix Computations. Here are my slides. Two new MATLAB functions, tred and imtql, instrumented to count flops, are available in symeig.m.... 続きを読む >>