Re: [Haskell-cafe] approximating pi

Assuming the square had 100 pixels per side, on the average, approximately how many random pixels should be plotted in the square before obtaining a reasonably good estimate of pi? Benjamin L. Russell --- On Mon, 4/28/08, jerzy.karczmarczuk@info.unicaen.fr wrote:

From: jerzy.karczmarczuk@info.unicaen.fr Subject: Re: [Haskell-cafe] approximating pi To: haskell-cafe@haskell.org Date: Monday, April 28, 2008, 9:54 AM Don Stewart writes:

...

Ry Dahl:

...

By picking points randomly from a square one can calculate pi. ... What is the best way to express this algorithm in Haskell?

Using a random generator, such as System.Random or System.Random.Mersenne, generate random numbers in your range, testing if they're inside the circle, and loop until your limit condition is reached.

The full program is about 10 lines or so, so shouldn't be too hard to work out, once you've worked out how to generate Doubles from System.Random.random

Ry Dahl seems to know Ruby. Ruby has also comprehensions. So, why not use 'randoms' to generate an infinite list of them, 'take' some N, and then 'sum' 1 on randoms filtered by the circle condition. I think that you won't need full 10 lines of code...

Jerzy Karczmarczuk

_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe