def invert_component(self, cls, w, z, h):
"""
Invert a single PLCA component to separated features in the original feature space.
"""
w = P.atleast_2d(w)
if cls == plca.PLCA: w = w.T
h = P.atleast_2d(h)
return cls.reconstruct(w, z, h)
def stack_vectors(data, win=1, hop=1, zero_pad=True):
"""
::
create an overlapping stacked vector sequence from a series of vectors
data - row-wise multidimensional data to stack
win - number of consecutive vectors to stack [1]
hop - number of vectors to advance per stack [1]
zero_pad - zero pad if incomplete stack at end
"""
data = pylab.atleast_2d(data)
nrows, dim = data.shape
hop = min(hop, nrows)
nvecs = nrows / int(hop) if not zero_pad else int(
pylab.ceil(nrows / float(hop)))
features = pylab.zeros((nvecs, win * dim))
i = 0
while i < nrows - win + 1:
features[i / hop, :] = data[i:i + win, :].reshape(1, -1)
i += hop
if i / hop < nvecs:
x = data[i::, :].reshape(1, -1)
features[i / hop, :] = pylab.c_[x,
pylab.zeros(
(1, win * dim - x.shape[1]))]
return features
def _pvoc2(self, X_hat, Phi_hat=None, R=None):
"""
::
alternate (batch) implementation of phase vocoder - time-stretch
inputs:
X_hat - estimate of signal magnitude
[Phi_hat] - estimate of signal phase
[R] - resynthesis hop ratio
output:
updates self.X_hat with modified complex spectrum
"""
N, W, H = self.nfft, self.wfft, self.nhop
R = 1.0 if R is None else R
dphi = P.atleast_2d((2 * P.pi * H * P.arange(N / 2 + 1)) / N).T
print("Phase Vocoder Resynthesis...", N, W, H, R)
A = P.angle(self.STFT) if Phi_hat is None else Phi_hat
U = P.diff(A, 1) - dphi
U = U - P.np.round(U / (2 * P.pi)) * 2 * P.pi
t = P.arange(0, n_cols, R)
tf = t - P.floor(t)
phs = P.c_[A[:, 0], U]
phs += U[:, idx[1]] + dphi # Problem, what is idx ?
Xh = (1 - tf) * Xh[:-1] + tf * Xh[1:]
Xh *= P.exp(1j * phs)
self.X_hat = Xh
def _phase_map(self):
self.dphi = (2 * P.pi * self.nhop *
P.arange(self.nfft / 2 + 1)) / self.nfft
A = P.diff(P.angle(self.STFT), 1) # Complete Phase Map
U = P.c_[P.angle(self.STFT[:, 0]), A - P.atleast_2d(self.dphi).T]
U = U - P.np.round(U / (2 * P.pi)) * 2 * P.pi
self.dPhi = U
return U
def _ichroma(self, V, **kwargs):
"""
::
Inverse chromagram transform. Make a signal from a folded constant-Q transform.
"""
if not (self._have_hcqft or self._have_cqft):
return None
a, b = self.HCQFT.shape if self._have_hcqft else self.CQFT.shape
complete_octaves = a / self.nbpo # integer division, number of complete octaves
if P.remainder(a, self.nbpo):
complete_octaves += 1
X = P.repeat(V, complete_octaves, 0)[:a, :] # truncate if necessary
X /= X.max()
X *= P.atleast_2d(P.linspace(1, 0,
X.shape[0])).T # weight the spectrum
self.x_hat = self._icqft(X, **kwargs)
return self.x_hat
def extract(self):
Features.extract(self)
mf = (self.X.T * self._logfrqs).sum(1) / self.X.T.sum(1)
self.X = (((self.X / self.X.T.sum(1)).T *
((P.atleast_2d(self._logfrqs).T - mf)).T)**2).sum(1)
