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 >>

My recent obsession with cubes in this blog has led me back to Rubik's cube, perhaps the greatest mathematical puzzle of all time.... 続きを読む >>

A few months ago, I had never heard of Karl Menger or the cube-like fractal that he invented. Now I have this long blog post about the sponge, and an extension that I am calling its "associate".... 続きを読む >>

A cube is the familiar three-dimensional solid with eight vertices, six faces and twelve edges. I have been working with cubes recently in posts about both the Menger sponge fractal and the 4-by-4 matrix from computer graphics.... 続きを読む >>

The Menger sponge is a popular fractal that generalizes Cantor sets and Sierpinski triangles. Its fractal dimension is between two and three.... 続きを読む >>

Matrices in action.... 続きを読む >>

Quaternions are generalizations of the complex numbers that have found applications in computer graphics and many other fields.... 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 >>

What do the years 2018, 2029 and 2040 have in common? They are the only years in the 21st century when Easter Sunday occurs on April Fools Day.... 続きを読む >>

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.... 続きを読む >>