Using J for Actuarial Applications – Part 1: The Chain-Ladder Method
1. Introduction This article is the first in a planned series. My goal is to illustrate how J can be used in an actuarial setting. Although I am a J enthusiast, I do not consider myself to be a highly skilled J programmer. I hope that by introducing these actuarial...
Sixteen APL Amuse-Bouches
The amuse-bouche is the best way … to express big ideas in small bites. – Jean-Georges Vongerichten, 2002 Such were the vagaries of what may have been the most powerful computer language ever hatched by a Canadian. Yes, I know that James Gosling, an alumnus of the...
Letting data tell a story with kdb+
Figure 1 – Using data to tell the story of a good game of tennis Introduction In tennis the addict moves about a hard rectangle and seeks to ambush a fuzzy ball with a modified snow shoe. In q the addict moves algorithms from their mind to the central processing unit...
Book review — Q Tips: Fast, Scalable and Maintainable Kdb+
For most people who approach a new language, the first question asked usually isn’t about syntax, features and functionality, but rather “what can it do”. Q, being as terse as it is, has relied on snippets, anecdotes and reference guides to try to answer this...
Second Childhood
Editor’s note The story below of what happened to The Childcare Company recounts events which have been the subject of legal proceedings. For this reason, the previous partners of The Childcare Company are not named here. Nor has Vector checked this account with them:...
J-ottings 58 — Internal Rate of Return and related topics
A common way of expressing the desirability or otherwise of an investment is through a rate of return. There are several ways in which ‘rate of return’ can be calculated. Comparisons between numbers are only meaningful if the processes producing the numbers are...
Reading New Code
Introduction One of the requirements to writing and debugging code is to understand how to read the language in the first place. This applies to any language including human languages. If you can't read English the following will be hard to understand. Case Study I...
Impending kOS
It began badly. We were walking along the South Downs Way in early summer, the sun glittering on the English Channel on our right, the Weald of Sussex stretching away to our left. “How big,” asked Arthur, “should a text editor be?” I’ve known Whitney most of my life....
Searching for the state in which Wonderful Things are inevitable
“Fear leads to anger, anger leads to hate,hate leads to suffering.”- Master Yoda I love this quote, fear is the mind killer; our minds are like parachutes, they don’t work unless they are open. If we feel threatened, we get defensive,we stop listening, we stop...
A tool of thought
I am often asked “what is APL good for”? I reply that APL is good for almost anything but that it is also very good at prototyping. With it you can experiment and use it as a tool for thinking about the problem at hand. It is easy in APL to manipulate data and build...