def grad_cd1(self, params, inputs, **kwargs):
"""
"""
g = gzeros(params.shape)
n, _ = inputs.shape
m_end = self.m_end
V = self.shape[0]
H = self.shape[1]
wm = params[:m_end].reshape(self.shape)
prec = params[-V:][:, gpu.newaxis]
h1, h_sampled = self.H(inputs, wm=prec*wm, bias=params[m_end:m_end+H], sampling=True)
v2, v_sampled = gauss(h_sampled, wm=(wm/prec).T, bias=params[-(2*V):-V], prec=prec.T, sampling=True)
h2, _ = self.H(v2, wm=prec*wm, bias=params[m_end:m_end+H])
#print h1[0,0], h_sampled[0,0], v2[0,0], v_sampled[0,0]
# Note the negative sign: the gradient is
# supposed to point into 'wrong' direction.
g[:m_end] = -gdot(inputs.T*prec, h1).ravel()
g[:m_end] += gdot(v_sampled.T*prec, h2).ravel()
g[:m_end] *= 1./n
g[:m_end] += self.l2*params[:m_end]
g[m_end:m_end+H] = -h1.sum(axis=0)
g[m_end:m_end+H] += h2.sum(axis=0)
g[m_end:m_end+H] *= 1./n
g[-2*V:-V] = -inputs.sum(axis=0)
g[-2*V:-V] += v_sampled.sum(axis=0)
g[-2*V:-V] *= 1./n
g[-2*V:-V] *= (prec**2).T
#print gsum(g[:m_end]**2), gsum(g[m_end:m_end+H]**2), gsum(g[-2*V:-V]**2)
# Gradient for square root of precision
g[-V:] = -gsum(2*prec.T*inputs*(params[-2*V:-V] - inputs/2), axis=0) + gsum(gdot(inputs.T, h1)*wm, axis=1)
g[-V:] += (gsum(2*prec.T*v_sampled*(params[-2*V:-V] - v_sampled/2), axis=0) + gsum(gdot(v_sampled.T, h2)*wm, axis=1))
g[-V:] *= 1./n
#print gsum(g[-V:]**2)
if self.lmbd > 0.:
if self.rho_hat is None:
self.rho_hat = h1.mean(axis=0)
else:
self.rho_hat *= 0.9
self.rho_hat += 0.1 * h1.mean(axis=0)
dKL_drho_hat = (self.rho - self.rho_hat)/(self.rho_hat*(1-self.rho_hat))
h1_1mh1 = h1*(1 - h1)
g[m_end:m_end+H] -= self.lmbd/n * gsum(h1_1mh1, axis=0) * dKL_drho_hat
g[:m_end] -= self.lmbd/n * (gdot(inputs.T * prec, h1_1mh1) * dKL_drho_hat).ravel()
#g[:] = -g[:]
return g
def reconstruction(self, params, inputs, **kwargs):
"""
"""
m_end = self.m_end
V = self.shape[0]
H = self.shape[1]
wm = params[:m_end].reshape(self.shape)
prec = params[-V:][:, gpu.newaxis]
h1, h_sampled = self.H(inputs, wm=prec*wm, bias=params[m_end:m_end+H], sampling=True)
v2, v_sampled = gauss(h_sampled, wm=(wm/prec).T, bias=params[-(2*V):-V], prec=prec.T, sampling=True)
rho_hat = h1.sum()
rec = gsum((inputs - v_sampled)**2)
return np.array([rec, self.lmbd*rho_hat])
def reconstruction(self, params, inputs, **kwargs):
"""
"""
m_end = self.m_end
V = self.shape[0]
H = self.shape[1]
wm = params[:m_end].reshape(self.shape)
prec = params[-V:][:, gpu.newaxis]
h1, h_sampled = self.H(inputs,
wm=prec * wm,
bias=params[m_end:m_end + H],
sampling=True)
v2, v_sampled = gauss(h_sampled,
wm=(wm / prec).T,
bias=params[-(2 * V):-V],
prec=prec.T,
sampling=True)
rho_hat = h1.sum()
rec = gsum((inputs - v_sampled)**2)
return np.array([rec, self.lmbd * rho_hat])
def grad_cd1(self, params, inputs, **kwargs):
"""
"""
g = gzeros(params.shape)
n, _ = inputs.shape
m_end = self.m_end
V = self.shape[0]
H = self.shape[1]
wm = params[:m_end].reshape(self.shape)
prec = params[-V:][:, gpu.newaxis]
h1, h_sampled = self.H(inputs,
wm=prec * wm,
bias=params[m_end:m_end + H],
sampling=True)
v2, v_sampled = gauss(h_sampled,
wm=(wm / prec).T,
bias=params[-(2 * V):-V],
prec=prec.T,
sampling=True)
h2, _ = self.H(v2, wm=prec * wm, bias=params[m_end:m_end + H])
#print h1[0,0], h_sampled[0,0], v2[0,0], v_sampled[0,0]
# Note the negative sign: the gradient is
# supposed to point into 'wrong' direction.
g[:m_end] = -gdot(inputs.T * prec, h1).ravel()
g[:m_end] += gdot(v_sampled.T * prec, h2).ravel()
g[:m_end] *= 1. / n
g[:m_end] += self.l2 * params[:m_end]
g[m_end:m_end + H] = -h1.sum(axis=0)
g[m_end:m_end + H] += h2.sum(axis=0)
g[m_end:m_end + H] *= 1. / n
g[-2 * V:-V] = -inputs.sum(axis=0)
g[-2 * V:-V] += v_sampled.sum(axis=0)
g[-2 * V:-V] *= 1. / n
g[-2 * V:-V] *= (prec**2).T
#print gsum(g[:m_end]**2), gsum(g[m_end:m_end+H]**2), gsum(g[-2*V:-V]**2)
# Gradient for square root of precision
g[-V:] = -gsum(2 * prec.T * inputs * (params[-2 * V:-V] - inputs / 2),
axis=0) + gsum(gdot(inputs.T, h1) * wm, axis=1)
g[-V:] += (gsum(2 * prec.T * v_sampled *
(params[-2 * V:-V] - v_sampled / 2),
axis=0) + gsum(gdot(v_sampled.T, h2) * wm, axis=1))
g[-V:] *= 1. / n
#print gsum(g[-V:]**2)
if self.lmbd > 0.:
if self.rho_hat is None:
self.rho_hat = h1.mean(axis=0)
else:
self.rho_hat *= 0.9
self.rho_hat += 0.1 * h1.mean(axis=0)
dKL_drho_hat = (self.rho - self.rho_hat) / (self.rho_hat *
(1 - self.rho_hat))
h1_1mh1 = h1 * (1 - h1)
g[m_end:m_end +
H] -= self.lmbd / n * gsum(h1_1mh1, axis=0) * dKL_drho_hat
g[:m_end] -= self.lmbd / n * (gdot(inputs.T * prec, h1_1mh1) *
dKL_drho_hat).ravel()
#g[:] = -g[:]
return g
