Ulam Spiral Code

ulam.hs

module Lib
     where

import Graphics.Gloss

density :: Float
density = 0.1

spiral :: [Float] -> [(Float, Float)]
spiral pts = map f pts
	where f t = (density * t * cos t, density * t * sin t)

primeSieve :: [Integer] -> [Integer]
primeSieve (x:xs) = x : (primeSieve $ filter (\y -> y `mod` x /= 0) xs)
primeSieve [] = []

primes :: [Integer]
primes = primeSieve [2..]

ulamSpiral :: [(Float, Float)]
ulamSpiral = spiral . map fromIntegral $ primes

pointRadius :: Float
pointRadius = 10

ulamPoint :: (Float, Float) -> Picture
ulamPoint (x, y) = translate x y $ circleSolid pointRadius

ulamPoints :: [Picture]
ulamPoints = map ulamPoint ulamSpiral


window :: Display
window = InWindow "Ulam Spiral" (200, 200) (0, 0)

someFunc :: IO ()
someFunc = display window white (pictures . take 1000 $ ulamPoints)