What's all this, then?

Graphs of Eggs

Apr 20, 2018 geometry jsxgraph

I recently came across some nice material on John Cook's blog about equations that described eggs.

It turns out there are vast number of equations whose graphs are egg-shaped: that is, basically ellipse shape, but with one end "rounder" than the other.

You can see lots at Jürgen Köller's Mathematische …

JSXGraph is a graphics package deveoped in Javascript, and which seems to be tailor-made for a static blog such as this. It consists of only two files: the javascript file itself, and an accompanying css file, which you can download. Alternaively you can simply link to the online files at the Javascript content …

The trinomial theorem

Apr 5, 2018 mathematics algebra

When I was teaching the binomial theorem (or, to be more accurate, the binomial expansion) to my long-suffering students, one of them asked me if there was a trinomial theorem. Well, of course there is, although in fact expanding sums of greater than two terms is generally not classed as a theorem described by the …

Playing with Hugo

Apr 3, 2018 hugo org

I've been using wordpress as my blogging platform since I first started, about 10 years ago. (In fact the first post I can find is dated March 30, 2008.) I chose wordpress.com back then because it was (a) free, and (b) supported mathematics through a version (or subset) of LaTeX. As I have used LaTeX extensively for …

Python GIS, and election results

Mar 31, 2018 GIS python voting

Election mapping

A few weeks ago there was a by-election in my local electorate (known as an electoral division) of Batman here in Australia. I was interested in comparing the results of this election with the previous election two years ago. In this division it's become a two-horse race: the Greens against the …

Presentations and the delight of js-reveal

Mar 11, 2018

Presentations are a modern bugbear. Anybody in academia or business, or any professional field really, will have sat through untold hours of presentations. And almost all of them are terrible. Wordy, uninteresting, too many "transition effects", low information content, you know as well as I do.

Pretty much …

The Vigenere cipher in haskell

Jan 23, 2018 cryptography haskell

Programming the Vigenère cipher is my go-to problem when learning a new language. It's only ever a few lines of code, but it's a pleasant way of getting to grips with some of the basics of syntax. For the past few weeks I've been wrestling with Haskell, and I've now got to the stage where a Vigenère program is in fact …

Analysis of a recent election

Dec 7, 2017 voting python

On November 18, 2017, a by-election was held in my suburb of Northcote, on account of the death by cancer of the sitting member. It turned into a two-way contest between Labor (who had held the seat since its inception in 1927), and the Greens, who are making big inroads into the inner city. The Greens candidate won, …

Programmable CAD

Nov 24, 2017 CAD

Every few years I decide to have a go at using a CAD package for the creation of 3D diagrams and shapes, and every time I give it up. There's simply too much to learn in terms of creating shapes, moving them about, and so on, and every system seems to have its own ways of doing things. My son (who is an expert in …

Jan 1, 0001

Post-election swings

So the Australian federal election of 2022 is over as far as the public is concerned; all votes have been cast and now it's a matter of waiting while the Australian Electoral Commission tallies the numbers, sorts all the preferences, and arrives at a result. Because of the complications of the …