def buildSharedCrossedNetwork():
""" build a network with shared connections. Two hiddne modules are symetrically linked, but to a different
input neuron than the output neuron. The weights are random. """
N = FeedForwardNetwork('shared-crossed')
h = 1
a = LinearLayer(2, name='a')
b = LinearLayer(h, name='b')
c = LinearLayer(h, name='c')
d = LinearLayer(2, name='d')
N.addInputModule(a)
N.addModule(b)
N.addModule(c)
N.addOutputModule(d)
m1 = MotherConnection(h)
m1.params[:] = scipy.array((1, ))
m2 = MotherConnection(h)
m2.params[:] = scipy.array((2, ))
N.addConnection(SharedFullConnection(m1, a, b, inSliceTo=1))
N.addConnection(SharedFullConnection(m1, a, c, inSliceFrom=1))
N.addConnection(SharedFullConnection(m2, b, d, outSliceFrom=1))
N.addConnection(SharedFullConnection(m2, c, d, outSliceTo=1))
N.sortModules()
return N
def _buildNetwork(*layers, **options):
"""This is a helper function to create different kinds of networks.
`layers` is a list of tuples. Each tuple can contain an arbitrary number of
layers, each being connected to the next one with IdentityConnections. Due
to this, all layers have to have the same dimension. We call these tuples
'parts.'
Afterwards, the last layer of one tuple is connected to the first layer of
the following tuple by a FullConnection.
If the keyword argument bias is given, BiasUnits are added additionally with
every FullConnection.
Example:
_buildNetwork(
(LinearLayer(3),),
(SigmoidLayer(4), GaussianLayer(4)),
(SigmoidLayer(3),),
)
"""
bias = options['bias'] if 'bias' in options else False
net = FeedForwardNetwork()
layerParts = iter(layers)
firstPart = iter(next(layerParts))
firstLayer = next(firstPart)
net.addInputModule(firstLayer)
prevLayer = firstLayer
for part in chain(firstPart, layerParts):
new_part = True
for layer in part:
net.addModule(layer)
# Pick class depending on whether we entered a new part
if new_part:
ConnectionClass = FullConnection
if bias:
biasUnit = BiasUnit('BiasUnit for %s' % layer.name)
net.addModule(biasUnit)
net.addConnection(FullConnection(biasUnit, layer))
else:
ConnectionClass = IdentityConnection
new_part = False
conn = ConnectionClass(prevLayer, layer)
net.addConnection(conn)
prevLayer = layer
net.addOutputModule(layer)
net.sortModules()
return net
def buildSlicedNetwork():
""" build a network with shared connections. Two hiddne modules are symetrically linked, but to a different
input neuron than the output neuron. The weights are random. """
N = FeedForwardNetwork('sliced')
a = LinearLayer(2, name = 'a')
b = LinearLayer(2, name = 'b')
N.addInputModule(a)
N.addOutputModule(b)
N.addConnection(FullConnection(a, b, inSliceTo=1, outSliceFrom=1))
N.addConnection(FullConnection(a, b, inSliceFrom=1, outSliceTo=1))
N.sortModules()
return N