In my previous blog post I reprinted the Cleve's Corner article from the 1995 issues of MATLAB News and Notes and SIAM News about the Pentium division bug. In today's post I would like to describe some of the effects that affair had on the emerging Internet, the MathWorks, and the Intel Corporation,... 続きを読む >>

The Pentium division bug episode in the fall of 1994 was a defining moment for the MathWorks, for the Internet, for Intel Corporation, and for me personally. In this blog I am reprinting the article that I wrote for the Winter 1995 issue of MATLAB News and Notes and for SIAM News. In my next blog I want to discuss the episode's impact.... 続きを読む >>

One of Jim Wilkinson's outstanding skills was his ability to pick great examples. A previous post featured his signature polynomial. This post features his signature matrices.... 続きを読む >>

The Quantum Matrix Processor, being announced today, is the world's first viable quantum array processor. Basic matrix operations are done instantaneously, with infinite procession. The programming environment is classic MATLAB.... 続きを読む >>

Easter Sunday is March 31 this year. Why? How is the date of Easter determined? ... 続きを読む >>

Wilkinson's polynomials are a family of polynmials with deceptively sensitive roots.... 続きを読む >>

I have already made several posts about gatlin, the image distributed with MATLAB of the organizing committee for the Gatlinburg III conference. From the MATLAB point of view, the first man on the left in the photo, J. H. Wilkinson, is by far the most important. From the early days of computers in the 1950s until his death in 1986, Wilkinson was the world's authority on matrix computation. His research on eigenvalue algorithms and their implementation in Algol led directly to EISPACK, the mathematical foundation for the first MATLAB.... 続きを読む >>

The inverse Hilbert matrix, invhilb, has recently made surprise appearances in Cody, the programming game on MATLAB Central, and one of Ned's posts in the MATLAB Spoken Here blog. Inverse Hilbert matrices had nearly been forgotten in MATLAB. Their comeback is due to the sign pattern of their entries. But I want to take you back to their original role demonstrating ill conditioning in numerical calculation.... 続きを読む >>

I investigated the reduced penultimate remainder algorithm in an undergraduate research project under professor John Todd at Caltech in 1961. I remember it today for two reasons. First, I learned what penultimate means. And second, it is the most obscure, impractical algorithm that I know. I suspect none of my readers have ever heard of it.... 続きを読む >>

Tuesday, January 8, 2013, would have been George Forsythe's 96th birthday. He passed away in 1972 at the age of 55. A pioneer in the establishment of computer science as an intellectual discipline, he was my Ph.D. thesis advisor, colleague, and friend.... 続きを読む >>