knuth

I often say professionally that I did a compsci major (though can never claim it officially) yonks ago but decided against becoming a programmer. That’s not a decision I regret mostly, though it must be said I continue to have strong leanings that direction. Scarily, it’s been over 25 years since those compsci days. Still, I learnt good stuff.

I recall in the second half of first year compsci, we had an older lecturer at the time who was actually a maths lecturer who seemed to have come across into computers. I can say “older” as I’ve just found this bio which sums up very briefly a rather fascinating career. He may even have been one of my favourite lecturers as he liked to play with new ideas and introduced stuff he knew about from maths into computing. I was a very rare beast in compsci in that I was enrolled under BA and not directly in Compsci and I did no math. I had done first year math but it wasn’t quite my bag. Doherty was very big on mathematical ideas and assessing efficiencies of algorithms.

I recall him talking some weird algorithm for encrypting data and he worked through the basic idea in a lecture, I think it was based on some sort of fractional encoding model. At the end of the lecture, he said the next assignment would be to implement it. I found the idea of it fascinating. The next assignment came out and sure enough it was on encryption so I implemented the algorithm in Pascal that he’d talked about based on my lecture notes. The idea was you’d write code to encrypt a paragraph of text, and code to decrypt the text. I was mostly successful but because it relied on decimal conversion of larger numbers, it rapidly lost accuracy on the 8 bit macs we were using at the time. Out of a sentence of 10 words, it started losing letters by the end of the first word.

Turns out, I should have read the back page of the assignment. Doherty had decided that the technique was a little too experimental for first year compsci and had instead instructed everyone to use a hashing technique. I handed my assignment in and discussed with the class tutor what I’d done. He wasn’t familiar with the algorithm at all but was impressed that it worked and understood why it failed where it did. I got full marks and first year compsci was one of my few high distinctions at uni.

mini computers on top of computer books.Anyway, Doherty would often quote Knuth as the foundation of modern computing. Knuth was all about the development of algorithms and understanding their efficiencies. Algorithms are really important as they represent techniques for solving particular sorts of problems eg what is the best way to sort a random string of numbers? The answer varies depending on how many numbers are in the string, or even whether you can know the number of numbers. For very small sets, a bubble sort is sufficient, and from there you move on to binary searches, binary trees, and so on. I wasn’t always across the math but really appreciated the underlying thinking around assessing approaches to problem solving. Plus Doherty was a fab lecturer with a bit of character.

So Knuth. He is best known for his series, The Art of Computer Programming, which has gone through a few editions and I wonder if it will ever be actually finished; the fourth volume is actually labeled 4A: Combinatorial Algorithms Part 1. Volume 4 is eventually expected to cover 4 volumes: 4A, 4B, 4C, 4D. 4B has been partially released across several fascicles of which 6 have been released. Volume 3 seems to be the most relevant for where I’m at today and where I’m looking to play; #3 is around 750 pages devoted specifically to sorting and searching. So much of what we do online is reliant on being able to find stuff and to find stuff well, it helps if the data has been ordered.

Knuth has this been this name in my head though my life has gone in other directions. A few years ago, I did a google and found that not only were his books on Amazon, there was even a box set of Volumes 1-4A. I bit the bullet about 3 years ago and bought the set, cost around US$180 at the time and looks really, bloody good on the shelf. I haven’t read a great deal yet but dipped in a few times and planning to get into volume 3 properly at some point. I’ve recently being moving stuff around at home and don’t have a lot of space for books next to where my computer gear is these days. However, it turns out, the mac mini sits nicely on top of the set, and my newest computer, the VivoMini sits nicely on top of the mac. I sorta like the idea of these small computers sitting on Knuth’s foundation.

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