Monthly Archives: October 2013

My computer can’t add (part 1)

I recently asked some of my colleagues a question relating to the Kahan compensated summation algorithm and was greeted with blank stares and the question “What’s that?”  This caught me off guard as I had known about it for a few years.  I can’t remember how I found out about it, but I think that journey started with a single tutorial question in 2nd year applied maths and when I read “What every computer scientist should know about floating-point arithmetic” by David Goldberg.  I’ll start this off with why this algorithm matters, then what it actually is. Continue reading


An odyssey learning about programming, maths, etc.

Over the past few years, I have benefited greatly from other people’s blogs, especially about computer programming, hardware, numerical analysis and 3D graphics.  I am by no means as bright as those people, nor do I have their years of experience, but I do occasionally find unusual problems who’s solutions I would like to share.  Of course, part of my reason for doing this is to record bits of my research and my thinking at the time so that I can find all this information when I forget it after a few months or years.

I feel it is necessary to point out that what I post here is only partly related to my PhD research.  Owing to intellectual property agreements I can’t blog about my actual work, but many of the tools I use and problems I encounter are more general than my little corner of the academic world, so I will keep their descriptions in this more general sense.