SSP.hs

import Graphics.Gnuplot.Simple

ts :: [Double]
ts = linearScale 100 (0, 1)
k :: Double
k = 1000.0
m :: Double
m = 12 / 6.02e23 / 1000

q1 t = (2.0 * pi / 3.0 * (1-t), 2.0 * pi / 3.0 * (1-t))
q2 t = (0.0, pi * t)
q3 t = (2.0 / 3.0 * pi * t, (3-t)*pi / 3)


dot :: (Double, Double) -> (Double, Double) -> Double
dot x y = fst x * fst y + snd x * snd y

w q t = sqrt $ (4*k/m*) $ s q (1, 0) t + s q (0, 1) t + s q (1,1) t
s q a t = (**2) $ sin $ dot (q t) a / 2


w1 = map (w q1) ts
w2 = map (w q2) ts
w3 = map (w q3) ts

ts1 = map (*2)ts 
ts2 = map ((+2) . (* sqrt 3)) ts
ts3 = map (2 + sqrt 3 + ) ts

main = plotPaths [Title "二次元の格子振動", PNG "ahya.png"] $ [zip ts1 w1, zip ts2 w2, zip ts3 w3]