# My First Computer, the Burroughs 205 Datatron

Posted by Cleve Moler,

The first computer that I seriously used was the Burroughs 205 Datatron. I actually used two different machines, one at Caltech for two years in 1959-61 and one at the University of Utah in the summer of 1960. Both the technology and the style of usage were wildly different from today's computers.... read more >>

Posted by Cleve Moler,

Do not get involved in a bar bet with Brad Efron and his dice until you have read this.... read more >>

# Householder Seminar HHXX on Numerical Linear Algebra2

Posted by Cleve Moler,

The Householder meetings on Numerical Linear Algebra have been held roughly every three years since 1961. The twentieth, with the logo HHXX, was held June 18th through 23rd at Virginia Tech in Blacksburg, Virginia. I've been to 17 of the meetings. They have been an important part of my professional life and I've written Cleve's Corner articles and blog posts about them, MathWorks News & Notes, and Householder XIX.... read more >>

# My Erdös Number and My Trump Number3

Posted by Cleve Moler,

I've long known that my Erdös Number is 3. This means that the length of the path on the graph of academic coauthorship between me and mathematician Paul Erdös is 3. Somewhat to my surprise, I recently discovered that I can also trace a chain of coauthorship to Donald J. Trump. My Trump number is 5.... read more >>

# Four Fundamental Subspaces of Linear Algebra, Corrected

Posted by Cleve Moler,

(Please replace the erroneous posting from yesterday, Nov. 28, with this corrected version.)... read more >>

# Four Fundamental Subspaces of Linear Algebra3

Posted by Cleve Moler,

Here is a very short course in Linear Algebra. The Singular Value Decomposition provides a natural basis for Gil Strang's Four Fundamental Subspaces.... read more >>

# Householder Reflections and the QR Decomposition1

Posted by Cleve Moler,

The QR decomposition is often the first step in algorithms for solving many different matrix problems, including linear systems, eigenvalues, and singular values. Householder reflections are the preferred tool for computing the QR decomposition.... read more >>

# Jim Sanderson, Two Careers: Computational Scientist and Conservationist3

Posted by Cleve Moler,

Jim Sanderson has had a fascinating professional life. He was my PhD student in math at the University of New Mexico in the 1970s. He spent almost 20 years as a computational scientist at Los Alamos National Laboratory, working on the lab’s supercomputers. He then developed an interest in ecology, went back to school, and is now the world’s leading authority on the preservation of small wild cats around the world…. read more >>

# Bug Report Revives Interest in SVD Option of “Eigshow”

Posted by Cleve Moler,

A few days ago we received email from Mike Hennessey, a mechanical engineering professor at the University of St. Thomas in St. Paul, Minnesota. He has been reading my book “Numerical Computing with MATLAB” very carefully. Chapter 7 is about “Eigenvalues and Singular Values” and section 10.3 is about one of my all-time favorite MATLAB demos, eigshow. Mike discovered an error in my description of the svd option of eigshow that has gone unnoticed in the over ten years that the book has been available from both the MathWorks web site and SIAM…. read more >>

# The Graeffe Root-Squaring Method for Computing the Zeros of a Polynomial1

Posted by Cleve Moler,

At a minisymposium honoring Charlie Van Loan this week during the SIAM Annual Meeting, I will describe several dubious methods for computing the zeros of polynomials. One of the methods is the Graeffe Root-squaring method, which I will demonstrate using my favorite cubic, $x^3-2x-5$.... read more >>