Sub/supersonic propeller sound and shock wave diagrams

gistfile1.hs

module Propeller where

import qualified Data.Foldable as F
import Diagrams.Prelude
import Diagrams.Backend.SVG
import Diagrams.Backend.SVG.CmdLine

type Diag = Diagram SVG R2

wave :: Double -> Double -> Diag
wave ang radius = circle radius # translate (r2 (0, 1)) # rotate (ang @@ rad)

waves :: Double -> Diag
waves speed = pad 1.1 $ unitCircle # lc red # lw thick <>
                    F.foldMap (\i -> let j = i * pi * 2 / density in wave (j * speed) j) [1..count]
  where
    density = 20
    count = density * 3 / 2

example :: Diag
example =
  waves 0.6
  ===
  waves 1.0
  ===
  waves 1.3

main = mainWith (example # lw veryThin)