def initialize_layers(self):
# Stack all layers except the last
for build_idx, (field_w, field_h, stride_w, stride_h, n_components,
poly_degree) in enumerate(self.layer_configurations):
if build_idx > 0 and (field_w == field_h == -1):
field_w = slicer.reconstruction_shape[0]
field_h = slicer.reconstruction_shape[1]
try:
input_shape = self.input_shape if build_idx == 0 else slicer.reconstruction_shape
slicer = ReceptiveSlicer(input_shape=input_shape,
field_size=(field_w, field_h),
strides=(stride_w, stride_h))
except AssertionError:
raise ValueError(
f"Layer {build_idx + 1}: Field ({field_w}, {field_h}) with stride ({stride_w}, {stride_h}) does not fit data dimension ({input_shape[0]}, {input_shape[1]})"
)
self.sequence.append(slicer)
if poly_degree > 1:
pre_expansion_sfa = SFA(n_components,
batch_size=self.internal_batch_size,
fill_mode=None)
self.sequence.append(pre_expansion_sfa)
expansion = PolynomialFeatures(poly_degree)
expansion.partial = expansion.fit
self.sequence.append(expansion)
self.sequence.append(AdditiveNoise(self.noise_std))
post_expansion_sfa = SFA(n_components,
batch_size=self.internal_batch_size,
fill_mode=None)
self.sequence.append(post_expansion_sfa)
self.sequence.append(Clipper(-4, 4))
reconstructor = ReceptiveRebuilder((slicer.reconstruction_shape))
self.sequence.append(reconstructor)
self.layer_outputs.append(slicer.reconstruction_shape)
if self.verbose > 0:
print(f"WxH output layer {build_idx + 1}: " +
str(slicer.reconstruction_shape))
# Flatten
self.sequence.append(Flatten())
# Last layer
if self.final_degree > 1:
pre_expansion_sfa = SFA(self.n_components,
batch_size=self.internal_batch_size,
fill_mode=None)
self.sequence.append(pre_expansion_sfa)
expansion = PolynomialFeatures(self.final_degree)
expansion.partial = expansion.fit
self.sequence.append(expansion)
self.sequence.append(AdditiveNoise(self.noise_std))
post_expansion_sfa = SFA(self.n_components,
batch_size=self.internal_batch_size,
fill_mode=None)
self.sequence.append(post_expansion_sfa)
self.sequence.append(Clipper(-4, 4))
if self.verbose > 0:
print("Shape of final output: " + str((self.n_components, )))
