class NaiveConvolutionalFeatureMap(BaseBPropComponent):
"""
One way to implement a standard feature map that takes input from a
single lower-level image. This serves two purposes: to demonstrate
how to write new learning modules by composing two existing modules,
and to serve as a sanity check for the more efficient implementation,
ConvolutionalFeatureMap.
Has, as members, a ConvolutionalPlane with standard bias configuration
and a TanhSigmoid object that does the squashing.
This is a little wasteful since each of the modules has separate output
array members. See FeatureMap for a slightly more memory efficient
implementation that uses subclassing.
"""
def __init__(self, fsize, imsize):
"""Construct a feature map with given filter size and image size."""
super(NaiveConvolutionalFeatureMap, self).__init__()
self.convolution = ConvolutionalPlane(fsize, imsize)
self.nonlinearity = TanhSigmoid(self.convolution.outsize)
def fprop(self, inputs):
"""Forward propagate input through this module."""
return self.nonlinearity.fprop(self.convolution.fprop(inputs))
def bprop(self, dout, inputs):
"""
Backpropagate derivatives through this module to get derivatives
with respect to this module's input.
"""
squash_inputs = self.convolution.fprop(inputs)
squash_derivs = self.nonlinearity.bprop(dout, squash_inputs)
return self.convolution.bprop(squash_derivs, inputs)
def grad(self, dout, inputs):
"""
Gradient of the error with respect to the parameters of this module.
Parameters:
* dout -- derivative of the outputs of this module
(will be size of input - size of filter + 1, elementwise)
* inputs -- inputs to this module
"""
squash_inputs = self.convolution.fprop(inputs)
squash_derivs = self.nonlinearity.bprop(dout, squash_inputs)
return self.convolution.grad(squash_derivs, inputs)
def initialize(self):
"""Initialize the module's weights."""
self.convolution.initialize()
@property
def outsize(self):
"""Output size."""
return self.convolution.outsize
@property
def imsize(self):
"""Image input size."""
return self.convolution.imsize
@property
def fsize(self):
"""Filter shape."""
return self.convolution.filter.shape
class NaiveConvolutionalFeatureMap(BaseBPropComponent):
"""
One way to implement a standard feature map that takes input from a
single lower-level image. This serves two purposes: to demonstrate
how to write new learning modules by composing two existing modules,
and to serve as a sanity check for the more efficient implementation,
ConvolutionalFeatureMap.
Has, as members, a ConvolutionalPlane with standard bias configuration
and a TanhSigmoid object that does the squashing.
This is a little wasteful since each of the modules has separate output
array members. See FeatureMap for a slightly more memory efficient
implementation that uses subclassing.
"""
def __init__(self, fsize, imsize):
"""Construct a feature map with given filter size and image size."""
super(NaiveConvolutionalFeatureMap, self).__init__()
self.convolution = ConvolutionalPlane(fsize, imsize)
self.nonlinearity = TanhSigmoid(self.convolution.outsize)
def fprop(self, inputs):
"""Forward propagate input through this module."""
return self.nonlinearity.fprop(self.convolution.fprop(inputs))
def bprop(self, dout, inputs):
"""
Backpropagate derivatives through this module to get derivatives
with respect to this module's input.
"""
squash_inputs = self.convolution.fprop(inputs)
squash_derivs = self.nonlinearity.bprop(dout, squash_inputs)
return self.convolution.bprop(squash_derivs, inputs)
def grad(self, dout, inputs):
"""
Gradient of the error with respect to the parameters of this module.
Parameters:
* dout -- derivative of the outputs of this module
(will be size of input - size of filter + 1, elementwise)
* inputs -- inputs to this module
"""
squash_inputs = self.convolution.fprop(inputs)
squash_derivs = self.nonlinearity.bprop(dout, squash_inputs)
return self.convolution.grad(squash_derivs, inputs)
def initialize(self):
"""Initialize the module's weights."""
self.convolution.initialize()
@property
def outsize(self):
"""Output size."""
return self.convolution.outsize
@property
def imsize(self):
"""Image input size."""
return self.convolution.imsize
@property
def fsize(self):
"""Filter shape."""
return self.convolution.filter.shape
