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.... 更多内容 >>

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.... 更多内容 >>

The answer: A\A is always I, except when it isn't.... 更多内容 >>

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.... 更多内容 >>

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.... 更多内容 >>

Computing Eigenvalues of Symmetric MatricesSee revision.Get the MATLAB code (requires JavaScript) Published with MATLAB®... 更多内容 >>

This is about linear systems with fewer equations than variables; A*x = b where the m -by- n matrix A has fewer rows that columns, so m < n . I have always called such systems wide or fat, but this is not respectful. So I consulted the Merriam-Webster Thesaurus and found commodious.... 更多内容 >>

I recently published Round, With Ties to Even and followed that with Round Two. Then, in an email, Andy Bartlett pointed out that my new round function fails for some large values of x between flintmax/2 and flintmax.... 更多内容 >>

I published Round, With Ties to Even a couple of days ago. Steve Eddins and Daniel Dolan immediately had substantive comments. Here is my reaction to their comments.... 更多内容 >>

We are considering a MATLAB Enhancement Request to support options for round(x) when x is exactly halfway between two integers.... 更多内容 >>