Posts filed under the 'Blog' category


Tightening the feedback loop when writing LaTeX expressions for MathJax

A couple of my recent blog posts have been about the Time Value of Money (one, two). They’re full of mathematical expressions, but I was tired of writing these expressions out in Microsoft Word’s equation editor, taking a snapshot of the result, and inserting the result as an image in the post. Instead I decided to try out MathJax, a quite remarkable JavaScript library that renders math expressions at run-time in the client. […]

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Time Value of Money (part 2)

Last time we discussed that money has a time component to it, that it changes value with time. We derived the basic formula for TVM (Time Value of Money): […]

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Time Value of Money (part 1)

Back in a previous life, I used to write swaps and options software for traders and brokers. Of all my jobs, I’d have to say that writing this kind of software was practically the only one that utilized my mathematics degree to any great extent, which I must admit is kind of depressing in a way. You’d think that programming is all about mathematics but, in reality, not so much. Sure, understanding lambda calculus is all very well, but you tend not to have to use it in your day-to-day work. (My friend and colleague Seth Juarez is perhaps the only other person I know who regularly uses “proper” mathematics in his work: he’s a fan of machine learning, and you can get his open-source library here for C# and .NET.) […]

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Samuel Youd (aka John Christopher) (1922-2012)

For some reason I missed this from a month or so back. I’m subscribed to David Langford’s Ansible newsletter on science fiction topics, but for some reason I missed reading March’s issue where he noted the death of John Christopher. […]

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Macro extension tubes

On a whim at the end of last week I bought a set of Vivitar macro extension tubes for my Canon XTi. These are pretty neat: they pass through the auto-focus and auto-exposure signals from the camera to the lens, making them easier to use. There are three in the set: a 13mm, 21mm, and 31mm tube. If my mathematics is correct, this makes seven possible tube lengths since you can combine them in any order (call them A, B, and C, then the possible combinations are A, B, C, AB, AC, BC, and ABC). […]

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Making this blog work as an app on the iPhone (the wrap up)

So far in this series (one, two, three) we have specialized content, detection of phone orientation, basics of being Web Clip capable, and a back to home page functionality. This post wraps it all up by removing the latter, implementing some simple Back button functionality, a “loading” indicator, and I do a little bit of code housekeeping too. […]

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Making this blog work as an app on the iPhone (part 3)

The story so far (one, two) is that I’ve simplified the content of this blog for viewing on the iPhone, I’ve added code that recognizes when the phone’s orientation is changed from portrait to landscape (and vice versa), and I’ve added the necessary elements to the head element to indicate that this site can be viewed as a Web Clip. With the current state of play though, the moment you touch on a link, Safari fires up to display the page. […]

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Making this blog work as an app on the iPhone (part 2)

Now that we have a special web site that displays properly either in portrait or landscape mode, let’s make it a web application that we pin to the Home screen. Boiled down to its essence, this is easy: you bring the web page up in Safari, touch the middle button in the bar at the bottom of the screen, and then select the Add to Home Screen option. […]

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Making this blog work as an app on the iPhone (part 1)

With the iPhone you easily view a web site in Safari, but you get the annoying bits of chrome at the top (the address bar) and at the bottom (the buttons). What if you wanted your site to occupy the whole of the screen? Well, you can pin the site to the Home screen and, provided that you make a few changes to the HTML, CSS, and JavaScript, you can make your site behave as if it were pretty much a native app. […]

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Kings College Mathematics Society photos

As I said a while back, I was a member of the Kings College London Mathematics Society (a.k.a., KCL MathSoc) during my undergrad years. Now that I have a new flatbed scanner, I’ve been asked to scan the society photos and post them here, so here goes. […]

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