import wave
class SoundFile:
def __init__(self, signal,lab=''):
self.file = wave.open('./test' + lab + '.wav', 'wb')
self.signal = signal
self.sr = 44100
def write(self):
self.file.setparams((1, 2, self.sr, 44100*4, 'NONE', 'noncompressed'))
self.file.writeframes(self.signal)
self.file.close()
mypi = float(pi)
from math import sin
@interact
def sinsound(freq_ratio = slider(1/144,1,1/144,1/12)):
hz1 = 440.0
hz2 = float(440.0*2^freq_ratio)
html('$\cos(\omega t) - \cos(\omega_0 t) = 2 \sin(\\frac{\omega + \omega_0}{2}t) \sin(\\frac{\omega - \omega_0}{2}t)$')
s2 = [sin(hz1*x*mypi*2)+sin(hz2*x*mypi*2) for x in srange(0,4,1/44100.0)]
s2m = max(s2)
s2f = [16384*x/s2m for x in s2]
s2str = ''.join(wave.struct.pack('h',x) for x in s2f)
lab="%1.2f"%float(freq_ratio)
f = SoundFile(s2str,lab=lab)
f.write()
pnum = 1500+int(500/freq_ratio)
show(list_plot(s2[0:pnum],plotjoined=True))
html('<embed src="cell://test'+ lab +'.wav" width="200" height="100"></embed>')
html('Frequencies: '+ '$\omega_0 = ' + str(hz1) + ' $, $\omega = '+latex(hz2) + '$')
