In [1]:

    

from bregman.suite import *


    

In [2]:

    

sr=48000.
n=128
f0=sr/n
k=4
x1 = sinusoid(f0=f0*(k), num_points=sr, sr=sr) # A sine wave
x2 = sinusoid(f0=f0*(k+10+.25), num_points=sr, sr=sr) # A sine wave
x = (x1 + x2) / sqrt(2)


    

In [3]:

    

F = LinearFrequencySpectrum(x, nfft=n, wfft=n, nhop=n, sample_rate=sr) # Congruent STFT analysis
F.feature_plot()


    

In [4]:

    

U = array(F._phase_map())
plot(F.X[k-1:k+2,:10].T)
grid()
legend(['k-1','k','k+1'],loc=4)
ylabel('abs(STFT)'); xlabel('Frame Index (hop=%d)'%F.nhop)
title('Magnitude either side of non-zero magnitude channel')
figure()
plot(U[k-1:k+2,:10].T/pi)
grid()
legend(['k-1','k','k+1'],loc=4)
ylabel('angle(STFT) / PI'); xlabel('Frame Index (hop=%d)'%F.nhop)
title('Phase either side of non-zero magnitude channel')


    

    
Out[4]:





<matplotlib.text.Text at 0xaf4e4c4c>






    













    

In [5]:

    

plot(F.dphi)


    

    
Out[5]:





[<matplotlib.lines.Line2D at 0xaf65fa0c>]






    

In [6]:

    

F.dphi[-1] - round(F.dphi[-3]/(2*pi))*2*pi


    

    
Out[6]:





12.566370614359187

In [7]:

    

print F.dphi[k]
plot(diff(unwrap(angle(F.STFT[k,:]))))
plot(diff(unwrap(angle(F.STFT[k+10,:]))))
ax = array(axis())
ax[2]=-pi
ax[3]=pi
ax = axis(ax)


    

    




25.1327412287






    

In [7]:

    




    

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