## Samstag, 29. Dezember 2012

### Men who stare at needles

Buffon's needle problem is a question first posed in the 18th century by Georges-Louis Leclerc, Comte de Buffon:

What is the probability that a needle thrown at a lined sheet of paper will cross a line?

This problem can be used to estimate π. If we set the nail size and the line distance = 1, the estimator can be calculated by:
$$\widehat{\pi}=\frac{2\cdot throws}{hits}$$
Because throwing 80.000 needles can be annoying, I created an implementation in R. The result took over two hours to render an is attached to this post. It was generated by saving multiple GIF files and combining them to a movie. Red needles are hits, the heading represents the current approximation of π.