Mathias Brandewinder on .NET, F#, VSTO and Excel development, and quantitative analysis / machine learning.
by Mathias 13. July 2010 14:45

Found on Epic Win FTW – The Sparklines of Excel 2010 are cool, but this is an Epic Win indeed. Pretty amazing, and another shining example of how Excel is used for lots of purposes, some of them probably never considered by Microsoft :)


by Mathias 8. July 2010 11:03

A new method of forecasting has been brought to my attention: Paul. Paul is an English-born octopus, currently living in Germany, and has been predicting with high accuracy the results of the German soccer team, by picking between two boxes marked with the flag of the two competing teams:

How unlikely is it that Paul would have such a string of correct forecasts? Pretty unlikely. If you assume that Paul’s picks were completely random, with a 50% chance of correctly calling the winner, the probability of making 11 good calls out of 12 comes down to 0.29%. Does this mean Paul is the next big thing in forecasting? It’s possible, but I don’t think so (this said with all due respect to Paul and his skills). Leonard Mlodinow, in his excellent book, The Drunkard's Walk, makes the following comment:

This example illustrates an important point: even with data significant at, say, the 3 percent level, if you test 100 nonpsychic people for psychic abilities […], you ought to expect a few people to show up as psychic.

Mallarme In other words, if a phenomenon is random, you should typically see the “average” case regularly, but you should also see highly unlikely cases happen from time to time – observing such a rare occurrence doesn’t contradict the randomness of the phenomenon. Or, in the words of the French poet Mallarmé, Un Coup de Dés Jamais N'Abolira Le Hasard (A throw of the Dice will Never Abolish Chance).

by Mathias 4. January 2010 18:52

Nothing says “we really value your work here” like a well-located, pleasant workspace. Next time you complain about your cube, remember – it can always be worse.



by Mathias 14. July 2009 06:58

While shopping at PetCo the other day, I saw this scene, and couldn’t get enough of it. It’s a great illustration of what happens when teamwork goes wrong. If I saw this in real life, I would feel sorry for the team, but the mice don’t seem to be suffering (besides some confusion), so sit back and enjoy the show, guilt-free.

by Mathias 18. June 2009 06:40

Mark Twain famously said “There are three kinds of lies: lies, damned lies and statistics”; in that light, I found the following anecdote – from “The Drunkard’s Walk”, a thoroughly enjoyable book so far - pretty funny.

Like most of his compatriots, Jules Henri Poincaré, the legendary French mathematician, took his bread seriously, and purchased a fresh loaf daily. Suspecting his baker was a cheat, he weights his loaves every day, and finds out the average weight is 950g instead of the 1000g advertised. He complains to the authorities – and his daily baguette suddenly becomes larger.

But now, instead of enjoying his good life, Poincaré still suspects his baker is a cheat, and keeps on measuring his bread for an entire year, and finds out that he now got mostly larger than 1000g loaves, and too few light ones. For him it’s great; but from a statistics standpoint, this doesn’t sound right: he should have roughly as many small and large loaves. Poincaré concludes that the baker is still cheating, but gives him the biggest loaf of his inventory every day to pacify him. He calls the authorities in again, who confirm he is right, and slam the baker.

The moral of the story: don’t lie to statisticians!


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