brainwagon

It was reported that an Iridium satellite and an “non-functional Russian satellite” collided yesterday. I was curious, so I did a bit of digging, and found out that NASA had reported that it was Iridium 33 and COSMOS-2251. A bit more work uncovered orbital elements for both objects, so I was able to plug in […]

In the days of slide rules, before electronic computers, many engineering problems were solved using nomograms (also known as nomographs). In its simplest form, a nomogram is a kind of graph that shows the relationship between three variables in a very special way: by drawing a line between values for any two variables, you find […]

Claude Shannon’s Mathematical Theory of Communication is probably one of the most influential papers of the 20th century. It spawned the entire field of information theory. And, it’s available via the following link: A Mathematical Theory of Communication

While exploring some related links from the previous video on analog computers, I ran across this very interesting link on creating fractals using video feedback. YouTube – How to make fractals without a computer. httpv://www.youtube.com/watch?v=Jj9pbs-jjis

A couple of years ago, I blogged about H. E. Dudeney’s Amusements in Mathematics. Today, I noticed that Project Gutenberg had released a copy of The Canterbury Puzzles by Henry Ernest Dudeney – Project Gutenberg. This book has quite a few more nominally mathematical puzzles than its sibling. In particular, it introduces the game Kayles, […]

A while ago, I got interested in reimplementing various versions of the Sieve of Eratosthenes. I eventually tacked together a threaded version that could calculate all the primes up to a trillion in about 20 minutes, and then kind of got bored. Today, however, there’s an interesting link to an article on Lambda the Ultimate […]

As some of you may have noticed, I occasionally like to write small programs to compute odd little mathematical curiousities. Something I hadn’t done in a long while was to use the Sieve of Eratosthenes to compute a bunch of prime numbers. I suspect that I wrote such a program very early in my exploration […]

I do like programming “for fun”, and this includes writing programs that, well, have been written hundreds of times before, but which I never have bothered doing. Often, this is just an exercise: freely available libraries often exist for many tasks which are considerably better than anything that I write. Nevertheless, I don’t consider it […]

Here is a good explanation of the FFT. I have used FFT libraries before, but I never really bothered to code one myself. The FFT Demystified.

In fact, at the moment, it’s the largest known prime, with over 9.8 million digits. As part of my pi day celebration yesterday, I was trying to review how I might speed up my C code which calculates pi to large numbers of digits. Most of the fast ways rely on fast multiplication, utilizing the […]

Tomorrow is 3/14, known as pi day, or Albert Einstein’s birthday. How better to celebrate than with a script in pi-thon? #!/usr/bin/env python from itertools import islice def g(q, r, t, i): while True: u, y =3*(3*i+1)*(3*i+2), (q*(27*i-12)+5*r) // (5 * t) yield y q, r, t, i = 10*q*i*(2*i-1), 10*u*(q*(5*i-2)+r-y*t), t*u, i+1 def pig(): […]

I can never remember these formulas, so I wrote this program. I’m putting it here so I won’t lose it, and so others may benefit. #include <stdio.h> #include <stdlib.h> #include <math.h> /* $Id$ * * Written by Mark VandeWettering. * * Any copyright would be pretty stupid. Use this code as you see * fit, […]

It’s the third game of the World Series, and the score is tied 0-0. If you can’t find any enjoyment in the reality of the game, perhaps the theoretical niceties of the game might provide some distraction: 11011110: Batting averages Me? I enjoy both. [tags]Baseball, Mathematics[/tags]

I pride myself on being able to carry out calculations in my head that cause most people to go for the calculator. Need to calculate a 15% tip? Divide the total bill by 10, and then divide by 2, and then add the results. Easy. Sometimes while exercising on a bike I try to factor […]

Today is 3/14, also known as Pi Day. Wish a “Happy Pi Day!” to your coworkers, and be forever branded as a math geek. Bonus links about pi. [tags]Mathematics,Transcendental Numbers,Pi[/tags]