console-wave

.gitignore

dist
cabal-dev
*.o
*.hi
*.chi
*.chs.h
.virtualenv
.hsenv
.cabal-sandbox/
cabal.sandbox.config
cabal.config

README.md

Print a sine wave to the terminal.

plotwave.hs

import Control.Concurrent (threadDelay)

putStrs :: [String] -> IO ()
putStrs (l:ls) = do
  putStrLn l
  threadDelay 50000
  putStrs ls

plotLines :: [Int] -> [String]
plotLines (x0:x1:xs) = line : plotLines xs
  where
    line = map charForPos [0 .. max x0 x1]
    charForPos :: Int -> Char
    charForPos pos
      | and $ map (== pos) [x0, x1] = '█'
      | x0 == pos                  = '▀'
      | x1 == pos                  = '▄'
      | otherwise                  = ' '

f :: Float -> Int
f x = round $ 40 + 40 * sin(x / 9)

main :: IO()
main = putStrs $ plotLines $ map f [1..]