M635 J520

A while back a friend of mine asked if I could automate the creation of groups in a class of students - to maximize the variation within each group, but minimize the difference between them. This sounded like an interesting problem, so I set about to solve it in my own naive experimental Monte Carlo (inspired) way - without looking into ways this has been solved (surely elegantly) before. The result was this little Ruby script: Loading... First I just require some code I have previously written. (I guess I really should make them into gems or something instead of copying code around...) names.rb  tries to guess sex from a person's name and/or title, and countries.rb  maps countries to continents, regions etc with some fuzzy matching of names. (I'm looking at you Democratic Republic of Kongo,  Koreas  etc.) Easy-peasy. Then I set some standard variables. (Maybe I'll make this dynamic in the future, why not?) The most interesting entry here is the classifiers ...

I noticed that my RVM-handled irb in OS X (Mountain Lion) didn't like Norwegian characters today. So instead of an 'ø' , I got '\U+FFC3\U+FFB8' during entry, and nothing afterwards. Like so: Not really satisfactory. After googling: "os x irb unicode characters rvm" I found the answer on stackoverflow . Almost. My adapted solution was this: So now I can do: Better. (Not quite sure why the '--verify-downloads 1' part is needed, but it did the trick.)

Inspired by my little son's eagerness to count when he sees groups of things that (he thinks) can be grouped together these days, I wanted to post my often used, tiny, fairly naïve extension to Ruby's Array class that I call count_by . This might not be the most beautiful way to solve this, but it is fairly readable and is leveraging some key aspects of the Ruby language - open classes, or monkey patching if you must, and dynamic calling of functions. Basically I open up the class Array and add a count_by function to it - that takes as argument the name of the function one wants to count the elements by. The function itself starts off by instantiating a Hash , called map , with default values of 0. For each element in the Array I then call the function by the name provided and increments the  entry in map  corresponding to the result. Like this, if I have a array of, let's say Olympic medalist objects with functions nationality in list , I can ...