A blog of Python-related topics and code.
Fireball statistics
Posted by: christian on 15 Nov 2017
In astronomy, a fireball is a meteor bright enough to be seen over a wide area (either apparent magnitude greater than -4 or greater than -3 at zenith, depending on the definition used). The terms bolide and, for exceptionally bright meteors, superbolide are also used. A famous recent example is the Chelyabinsk meteor.
Muller's Recurrence
Posted by: christian on 11 Nov 2017
The recurrence devised by Jean-Michel Muller[1] and described in a slightly modified form by William Kahan in a 2006 monograph[2] provides an interesting example of how the finite precision of floating point arithmetic can lead to wildly incorrect results in some circumstances.
Superellipses
Posted by: christian on 3 Nov 2017
A superellipse (also called a Lamé curve) is the curve described by the equation $$ \left|\frac{x}{a}\right|^p + \left|\frac{y}{b}\right|^p = 1 $$ For $n=2$, this is the equation of an ordinary ellipse and for $a=b=1$ that ellipse is a circle. The corresponding curve for $p=4$ is sometimes called a squircle.
Cobweb plots
Posted by: christian on 1 Nov 2017
A cobweb plot is often used to visulaize the behaviour of an iterated function. That is, the sequence of values obtained from setting $x_{n+1} = f(x_n)$, starting at some value $x_0$.
Evolution of a free particle
Posted by: christian on 28 Oct 2017
This post is based on Problem 2.22 from Griffiths, Introduction to Quantum Mechanics (Prentice Hall, 1995).