def __init__(self,
n_neurons,
dimensions,
recurrent_synapse=0.005,
readout_synapse=None,
radii=1.0,
gain=1.25,
rng=None,
neuron_type=Tanh(),
include_bias=True,
ens_seed=None,
label=None,
seed=None,
add_to_container=None,
**ens_kwargs):
"""Initializes the Echo State Network.
Parameters
----------
n_neurons : int
The number of neurons to use in the reservoir.
dimensions : int
The dimensionality of the input signal.
recurrent_synapse : nengo.synapses.Synapse (Default: ``0.005``)
Synapse used to filter the recurrent connection.
readout_synapse : nengo.synapses.Synapse (Default: ``None``)
Optional synapse to filter all of the outputs before solving
for the linear readout. This is included in the connection to the
``output`` Node created within the network.
radii : scalar or array_like, optional (Default: ``1``)
The radius of each dimension of the input signal, used to normalize
the incoming connection weights.
gain : scalar, optional (Default: ``1.25``)
A scalar gain on the recurrent connection weight matrix.
rng : ``numpy.random.RandomState``, optional (Default: ``None``)
Random state used to initialize all weights.
neuron_type : ``nengo.neurons.NeuronType`` optional \
(Default: ``Tanh()``)
Neuron model to use within the reservoir.
include_bias : ``bool`` (Default: ``True``)
Whether to include a bias current to the neural nonlinearity.
This should be ``False`` if the neuron model already has a bias,
e.g., ``LIF`` or ``LIFRate``.
ens_seed : int, optional (Default: ``None``)
Seed passed to the ensemble of neurons.
"""
Network.__init__(self, label, seed, add_to_container)
self.n_neurons = n_neurons
self.dimensions = dimensions
self.recurrent_synapse = recurrent_synapse
self.radii = radii # TODO: make array or scalar parameter?
self.gain = gain
self.rng = np.random if rng is None else rng
self.neuron_type = neuron_type
self.include_bias = include_bias
self.W_in = (self.rng.rand(self.n_neurons, self.dimensions) -
0.5) / self.radii
if self.include_bias:
self.W_bias = self.rng.rand(self.n_neurons, 1) - 0.5
else:
self.W_bias = np.zeros((self.n_neurons, 1))
self.W = self.rng.rand(self.n_neurons, self.n_neurons) - 0.5
self.W *= self.gain / max(abs(eig(self.W)[0]))
with self:
self.ensemble = nengo.Ensemble(self.n_neurons,
1,
neuron_type=self.neuron_type,
seed=ens_seed,
**ens_kwargs)
self.input = nengo.Node(size_in=self.dimensions)
pool = self.ensemble.neurons
nengo.Connection(self.input,
pool,
transform=self.W_in,
synapse=None)
nengo.Connection( # note the bias will be active during training
nengo.Node(output=1, label="bias"),
pool,
transform=self.W_bias,
synapse=None)
nengo.Connection(self.ensemble.neurons,
pool,
transform=self.W,
synapse=self.recurrent_synapse)
Reservoir.__init__(self,
self.input,
pool,
readout_synapse=readout_synapse,
network=self)
def __init__(self, n_neurons, dimensions, recurrent_synapse=0.005,
readout_synapse=None, radii=1.0, gain=1.25, rng=None,
neuron_type=Tanh(), include_bias=True, ens_seed=None,
label=None, seed=None, add_to_container=None, **ens_kwargs):
"""Initializes the Echo State Network.
Parameters
----------
n_neurons : int
The number of neurons to use in the reservoir.
dimensions : int
The dimensionality of the input signal.
recurrent_synapse : nengo.synapses.Synapse (Default: ``0.005``)
Synapse used to filter the recurrent connection.
readout_synapse : nengo.synapses.Synapse (Default: ``None``)
Optional synapse to filter all of the outputs before solving
for the linear readout. This is included in the connection to the
``output`` Node created within the network.
radii : scalar or array_like, optional (Default: ``1``)
The radius of each dimension of the input signal, used to normalize
the incoming connection weights.
gain : scalar, optional (Default: ``1.25``)
A scalar gain on the recurrent connection weight matrix.
rng : ``numpy.random.RandomState``, optional (Default: ``None``)
Random state used to initialize all weights.
neuron_type : ``nengo.neurons.NeuronType`` optional \
(Default: ``Tanh()``)
Neuron model to use within the reservoir.
include_bias : ``bool`` (Default: ``True``)
Whether to include a bias current to the neural nonlinearity.
This should be ``False`` if the neuron model already has a bias,
e.g., ``LIF`` or ``LIFRate``.
ens_seed : int, optional (Default: ``None``)
Seed passed to the ensemble of neurons.
"""
Network.__init__(self, label, seed, add_to_container)
self.n_neurons = n_neurons
self.dimensions = dimensions
self.recurrent_synapse = recurrent_synapse
self.radii = radii # TODO: make array or scalar parameter?
self.gain = gain
self.rng = np.random if rng is None else rng
self.neuron_type = neuron_type
self.include_bias = include_bias
self.W_in = (
self.rng.rand(self.n_neurons, self.dimensions) - 0.5) / self.radii
if self.include_bias:
self.W_bias = self.rng.rand(self.n_neurons, 1) - 0.5
else:
self.W_bias = np.zeros((self.n_neurons, 1))
self.W = self.rng.rand(self.n_neurons, self.n_neurons) - 0.5
self.W *= self.gain / max(abs(eig(self.W)[0]))
with self:
self.ensemble = nengo.Ensemble(
self.n_neurons, 1, neuron_type=self.neuron_type, seed=ens_seed,
**ens_kwargs)
self.input = nengo.Node(size_in=self.dimensions)
pool = self.ensemble.neurons
nengo.Connection(
self.input, pool, transform=self.W_in, synapse=None)
nengo.Connection( # note the bias will be active during training
nengo.Node(output=1, label="bias"), pool,
transform=self.W_bias, synapse=None)
nengo.Connection(
self.ensemble.neurons, pool, transform=self.W,
synapse=self.recurrent_synapse)
Reservoir.__init__(
self, self.input, pool, readout_synapse=readout_synapse,
network=self)
