Published
Further Twists of the Moebius Strip
The equations generating a surf plot of the Moebius strip can be parameterized and the parameters allowed to take on...
10 years ago
Published
The Eigenwalker Model of the Human Gait
A model of the human gait, developed by Nikolaus Troje, is a five-term Fourier series with vector-valued coefficients that...
10 years ago
Published
Dark Energy Gravitational Waves
Recent theoretical, observational and computational results establish the possibility that gravitational waves produced by...
10 years ago
Submitted
Numerical Computing with MATLAB
Toolbox containing files and app from Numerical Computing with MATLAB
10 years ago | 122 downloads |
Published
Piet Hein, Super Ellipses and Soma Cubes
An extraordinarily creative Danish mathematician, inventor, and poet who often wrote under the Old Norse pseudonym...
10 years ago
Published
Investigating the Classic Crossed Ladders Puzzle
Today's blog post is a complete working MATLAB program investigating the crossed ladders problem. Download a copy of the...
10 years ago
Published
The Classic Crossed Ladders Puzzle
Here is a classic puzzle. A pair of ladders leaning against the sides of an alley form a lopsided cross. Each ladder is...
10 years ago
Published
How Many Times Should You Shuffle the Cards?
We say that a deck of playing cards is completely shuffled if it is impossible to predict which card is coming next when...
10 years ago
Published
Perfect Shuffles of Playing Cards
When a deck of playing cards is shuffled perfectly, the result is not random. A perfect shuffle places the cards in a...
10 years ago
Published
Fractal Global Behavior of Newton’s Method
When the starting point of Newton's method is not close to a zero of the function, the global behavior can appear to be...
10 years ago
Published
Testing Zero Finders
Use the historic cubic polynomial $x^3 - 2x - 5$ to test a few zero-finding algorithms. ...
10 years ago
Published
A Historic Cubic
The cubic polynomial $x^3 - 2x - 5$ has a unique place in the history of numerical methods....
10 years ago
Published
John Todd, Savior of Oberwolfach
This is the story of how John Todd saved what was to become one of the world's most important research institutions from...
10 years ago
Published
Trip Report: SuperComputing 2015
SC15, the International Conference for High Performance Computing, Networking, Storage and Analysis, was held in Austin,...
10 years ago
Published
Zeroin, Part 3: MATLAB Zero Finder, FZERO
MATLAB adds capability to search for an interval with a sign change....
10 years ago
Published
Zeroin, Part 2: Brent’s Version
Richard Brent's improvements to Dekker's zeroin algorithm, published in 1971, made it faster, safer in floating point...
10 years ago
Published
Zeroin, Part 1: Dekker’s Algorithm
Th. J. Dekker's zeroin algorithm from 1969 is one of my favorite algorithms. An elegant technique combining bisection and...
10 years ago
Published
Charles Lawson, 1931 – 2015
Chuck Lawson passed away in July at the age of 83. Chuck was one of the people who introduced me to computing and...
10 years ago
Published
Trip Report: Trefethen Birthday Conference
"New Directions in Numerical Computation" was a conference in celebration of Nick Trefethen's 60th birthday held August...
10 years ago
Published
Golub Matrices, Deceptively Ill Conditioned
I got the idea for these test matrices from Gene Golub years ago, but the mathematical foundation comes from a paper by...
10 years ago
Published
Tumbling Box ODE
A rectangular box, such as a book or a cell phone, thrown in the air can tumble stably about its longest axis, or about its...
10 years ago
Published
Discover e with a graphical experiment
An interactive graphical experiment lets you discover the value of one of the most important numerical quantities in...
10 years ago
Published
Trip Report: NACONF 2015 and Sparse Days III
I have just returned from two meetings in Europe, the 26th Biennial Conference on Numerical Analysis at the University of...
10 years ago
Published
Dubrulle Creates A Faster Tridiagonal QR Algorithm
Augustin (Austin) Dubrulle deserves to be better known in the numerical linear algebra community. His version of the...
10 years ago
Published
ALGOL 60, PL/0 and MATLAB
The 1960 programming language ALGOL 60 influenced the design of many subsequent languages, including C and a miniature...
10 years ago
Published
Friedrich Bauer
Fritz Bauer, eminent German computer scientist and last surviving member of the organizing committee of the 1964 Gatlingburg...
10 years ago
Answered
Accuracy of eig in support of complex step differentation: Derivative estimate accuracy degrades when step gets too small
I had forgotten about Nick Higham's comment after my blog post referencing his paper, "The complex step approximation to the Fr...
Accuracy of eig in support of complex step differentation: Derivative estimate accuracy degrades when step gets too small
I had forgotten about Nick Higham's comment after my blog post referencing his paper, "The complex step approximation to the Fr...
10 years ago | 2
Answered
Accuracy of eig in support of complex step differentation: Derivative estimate accuracy degrades when step gets too small
But you should not have to resort to complex step differentiation because an analytic expression for the derivative of an eigenv...
Accuracy of eig in support of complex step differentation: Derivative estimate accuracy degrades when step gets too small
But you should not have to resort to complex step differentiation because an analytic expression for the derivative of an eigenv...
10 years ago | 2
Answered
Accuracy of eig in support of complex step differentation: Derivative estimate accuracy degrades when step gets too small
I have to admit that I am unsure about what is going on here. Complex step differentiation relies upon the unperturbed function...
Accuracy of eig in support of complex step differentation: Derivative estimate accuracy degrades when step gets too small
I have to admit that I am unsure about what is going on here. Complex step differentiation relies upon the unperturbed function...
10 years ago | 2
| accepted