from scitools.sound import *
from scitools.all import *

def oscillations(N):
    x = zeros(N+1)
    for n in range(N+1):
        x[n] = exp(-4*n/float(N))*sin(8*pi*n/float(N))
    return x

def logistic(N):
    x = zeros(N+1)
    x[0] = 0.01
    q = 2
    for n in range(1, N+1):
        x[n] = x[n-1] + q*x[n-1]*(1 - x[n-1])
    return x

def make_sound(N, seqtype):
    filename = 'tmp.wav'
    x = eval(seqtype)(N)
    # convert x values to frequences around 440:
    freqs = 440 + x*200
    plot(range(N+1), freqs, 'ro')
    # generate tones:
    tones = []
    duration = 30.0/N     # 30 sec sound in total
    for n in range(N+1):
        tones.append(max_amplitude*note(freqs[n], duration, 1))
    data = concatenate(tones)
    write(data, filename)
    data = read(filename)
    play(filename)

if __name__ == '__main__':
    try:
        seqtype = sys.argv[1]
        N = int(sys.argv[2])
    except IndexError:
        print 'Usage: %s oscillations|logistic N' % sys.argv[0]
        sys.exit(1)
    make_sound(N, seqtype)