A few days ago, a bug report from our office in Cambridge caught my attention. Computing the singular values and singular vectors of a particular matrix would sometimes cause MATLAB to crash.... 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 >>

This blog post describes Qube, my Rubik's Cube simulator. Source code for Qube is now available in one single file from this link: Qube_osf.m. I will also submit the code to the MATLAB Central File Exchange. As usual, I welcome any feedback.... 続きを読む >>

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.... 続きを読む >>

The rank of a linear transformation is a fundamental concept in linear algebra and matrix factorizations are fundamental concepts in numerical linear algebra. Gil Strang's 2020 Vision of Linear Algebra seeks to introduce these notions early in an introductory linear algebra course.... 続きを読む >>

I have added this section to my post a few weeks ago about using the SVD to measure partisanship in the United States Senate.... 続きを読む >>

Many observers have noted that the United States Senate has become increasingly partisan in recent years. Votes are being made more frequently along strict political party lines. The singular value decomposition, the SVD, of matrices derived from records of roll call votes in the senate can measure this partisanship.... 続きを読む >>

Tomorrow, February 29, 2020 would be Gene Golub's 22nd birthday.... 続きを読む >>

The QR algorithm is one of the world's most successful algorithms. We can use animated gifs to illustrate three variants of the algorithm, one for computing the eigenvalues of a nonsymmetric... 続きを読む >>

This is a summary of my talk at the conference Celebrating the Centenary of James H. Wilkinson's Birth at the University of Manchester, May 29.... 続きを読む >>