def test_inputgatedmemory(Simulator, plt, seed):
to_memorize = 0.5
start_memorizing = 0.4
with nengo.Network(seed=seed) as net:
test_input = nengo.Node(piecewise(
{0.0: 0, 0.1: to_memorize, start_memorizing + 0.1: 0}))
gate_input = nengo.Node(piecewise({0.0: 0, start_memorizing: 1}))
reset_input = nengo.Node(0)
mem = nengo.networks.InputGatedMemory(100, 1, difference_gain=5.0)
nengo.Connection(test_input, mem.input)
nengo.Connection(gate_input, mem.gate)
nengo.Connection(reset_input, mem.reset)
mem_p = nengo.Probe(mem.output, synapse=0.01)
sim = Simulator(net)
sim.run(0.5)
data = sim.data[mem_p]
t = sim.trange()
plt.title("gating at %.1f s" % start_memorizing)
plt.plot(t, data, label="value in memory")
plt.axhline(to_memorize, c='k', lw=2, label="value to remember")
plt.axvline(start_memorizing, c='k', ls=':', label="start gating")
plt.legend(loc='best')
assert abs(np.mean(data[t < 0.1])) < 0.01
assert abs(np.mean(data[(t > 0.2) & (t <= 0.4)]) - 0.5) < 0.02
assert abs(np.mean(data[t > 0.4]) - 0.5) < 0.02
def test_inputgatedmemory(Simulator):
with nengo.Network(seed=123) as net:
test_input = nengo.Node(piecewise({0.0: 0, 0.3: 0.5, 1.0: 0}))
gate_input = nengo.Node(piecewise({0.0: 0, 0.8: 1}))
reset_input = nengo.Node(0)
mem = nengo.networks.InputGatedMemory(100, 1, difference_gain=5.0)
nengo.Connection(test_input, mem.input)
nengo.Connection(gate_input, mem.gate)
nengo.Connection(reset_input, mem.reset_node)
mem_p = nengo.Probe(mem.output, synapse=0.01)
sim = Simulator(net)
sim.run(1.2)
data = sim.data[mem_p]
trange = sim.trange()
with Plotter(Simulator) as plt:
plt.plot(trange, data)
plt.savefig('test_workingmemory.test_inputgatedmemory.pdf')
plt.close()
assert abs(np.mean(data[trange < 0.3])) < 0.01
assert abs(np.mean(data[(trange > 0.8) & (trange < 1.0)]) - 0.5) < 0.02
assert abs(np.mean(data[trange > 1.0]) - 0.5) < 0.02
def test_inputgatedmemory(Simulator, plt, seed):
to_memorize = 0.5
start_memorizing = 0.4
with nengo.Network(seed=seed) as net:
test_input = nengo.Node(
piecewise({
0.0: 0,
0.1: to_memorize,
start_memorizing + 0.1: 0
}))
gate_input = nengo.Node(piecewise({0.0: 0, start_memorizing: 1}))
reset_input = nengo.Node(0)
mem = nengo.networks.InputGatedMemory(100, 1, difference_gain=5.0)
nengo.Connection(test_input, mem.input)
nengo.Connection(gate_input, mem.gate)
nengo.Connection(reset_input, mem.reset)
mem_p = nengo.Probe(mem.output, synapse=0.01)
sim = Simulator(net)
sim.run(0.5)
data = sim.data[mem_p]
t = sim.trange()
plt.title("gating at %.1f s" % start_memorizing)
plt.plot(t, data, label="value in memory")
plt.axhline(to_memorize, c='k', lw=2, label="value to remember")
plt.axvline(start_memorizing, c='k', ls=':', label="start gating")
plt.legend(loc='best')
assert abs(np.mean(data[t < 0.1])) < 0.01
assert abs(np.mean(data[(t > 0.2) & (t <= 0.4)]) - 0.5) < 0.02
assert abs(np.mean(data[t > 0.4]) - 0.5) < 0.02
def test_integrator(Simulator, nl, plt):
model = nengo.Network(label='Integrator', seed=892)
with model:
model.config[nengo.Ensemble].neuron_type = nl()
inputs = {0: 0, 0.2: 1, 1: 0, 2: -2, 3: 0, 4: 1, 5: 0}
input = nengo.Node(piecewise(inputs))
tau = 0.1
T = nengo.networks.Integrator(tau, n_neurons=100, dimensions=1)
nengo.Connection(input, T.input, synapse=tau)
A = nengo.Ensemble(100, dimensions=1)
nengo.Connection(A, A, synapse=tau)
nengo.Connection(input, A, transform=tau, synapse=tau)
input_p = nengo.Probe(input)
A_p = nengo.Probe(A, synapse=0.01)
T_p = nengo.Probe(T.ensemble, synapse=0.01)
sim = Simulator(model, dt=0.001)
sim.run(6.0)
t = sim.trange()
plt.plot(t, sim.data[A_p], label='Manual')
plt.plot(t, sim.data[T_p], label='Template')
plt.plot(t, sim.data[input_p], 'k', label='Input')
plt.legend(loc=0)
assert rmse(sim.data[A_p], sim.data[T_p]) < 0.2
def test_integrator(Simulator, nl):
model = nengo.Network(label='Integrator', seed=892)
with model:
model.config[nengo.Ensemble].neuron_type = nl()
inputs = {0: 0, 0.2: 1, 1: 0, 2: -2, 3: 0, 4: 1, 5: 0}
input = nengo.Node(piecewise(inputs))
tau = 0.1
T = nengo.networks.Integrator(tau, n_neurons=100, dimensions=1)
nengo.Connection(input, T.input, synapse=tau)
A = nengo.Ensemble(100, dimensions=1)
nengo.Connection(A, A, synapse=tau)
nengo.Connection(input, A, transform=tau, synapse=tau)
input_p = nengo.Probe(input)
A_p = nengo.Probe(A, synapse=0.01)
T_p = nengo.Probe(T.ensemble, synapse=0.01)
sim = Simulator(model, dt=0.001)
sim.run(6.0)
with Plotter(Simulator, nl) as plt:
t = sim.trange()
plt.plot(t, sim.data[A_p], label='Manual')
plt.plot(t, sim.data[T_p], label='Template')
plt.plot(t, sim.data[input_p], 'k', label='Input')
plt.legend(loc=0)
plt.savefig('test_integrator.test_integrator.pdf')
plt.close()
assert rmse(sim.data[A_p], sim.data[T_p]) < 0.2
def test_node_to_neurons(Simulator, nl_nodirect):
name = "node_to_neurons"
N = 30
m = nengo.Network(label=name, seed=123)
with m:
m.config[nengo.Ensemble].neuron_type = nl_nodirect()
a = nengo.Ensemble(N, dimensions=1)
inn = nengo.Node(output=np.sin)
inh = nengo.Node(piecewise({0: 0, 2.5: 1}))
nengo.Connection(inn, a)
nengo.Connection(inh, a.neurons, transform=[[-2.5]] * N)
inn_p = nengo.Probe(inn, "output")
a_p = nengo.Probe(a, "decoded_output", synapse=0.1)
inh_p = nengo.Probe(inh, "output")
sim = Simulator(m)
sim.run(5.0)
t = sim.trange()
ideal = np.sin(t)
ideal[t >= 2.5] = 0
with Plotter(Simulator, nl_nodirect) as plt:
plt.plot(t, sim.data[inn_p], label="Input")
plt.plot(t, sim.data[a_p], label="Neuron approx, synapse=0.1")
plt.plot(t, sim.data[inh_p], label="Inhib signal")
plt.plot(t, ideal, label="Ideal output")
plt.legend(loc=0, prop={"size": 10})
plt.savefig("test_connection.test_" + name + ".pdf")
plt.close()
assert np.allclose(sim.data[a_p][-10:], 0, atol=0.1, rtol=0.01)
def test_node_to_neurons(Simulator, nl_nodirect):
name = 'node_to_neurons'
N = 30
m = nengo.Network(label=name, seed=123)
with m:
m.config[nengo.Ensemble].neuron_type = nl_nodirect()
a = nengo.Ensemble(N, dimensions=1)
inn = nengo.Node(output=np.sin)
inh = nengo.Node(piecewise({0: 0, 2.5: 1}))
nengo.Connection(inn, a)
nengo.Connection(inh, a.neurons, transform=[[-2.5]] * N)
inn_p = nengo.Probe(inn, 'output')
a_p = nengo.Probe(a, 'decoded_output', synapse=0.1)
inh_p = nengo.Probe(inh, 'output')
sim = Simulator(m)
sim.run(5.0)
t = sim.trange()
ideal = np.sin(t)
ideal[t >= 2.5] = 0
with Plotter(Simulator, nl_nodirect) as plt:
plt.plot(t, sim.data[inn_p], label='Input')
plt.plot(t, sim.data[a_p], label='Neuron approx, synapse=0.1')
plt.plot(t, sim.data[inh_p], label='Inhib signal')
plt.plot(t, ideal, label='Ideal output')
plt.legend(loc=0, prop={'size': 10})
plt.savefig('test_connection.test_' + name + '.pdf')
plt.close()
assert np.allclose(sim.data[a_p][-10:], 0, atol=.1, rtol=.01)
def test_ensemble_to_neurons(Simulator, nl_nodirect, plt, seed):
N = 30
m = nengo.Network(seed=seed)
with m:
m.config[nengo.Ensemble].neuron_type = nl_nodirect()
a = nengo.Ensemble(N, dimensions=1)
b = nengo.Ensemble(N, dimensions=1)
inn = nengo.Node(output=np.sin)
inh = nengo.Node(piecewise({0: 0, 0.5: 1}))
nengo.Connection(inn, a)
nengo.Connection(inh, b)
nengo.Connection(b, a.neurons, transform=[[-2.5]] * N)
inn_p = nengo.Probe(inn, 'output')
a_p = nengo.Probe(a, 'decoded_output', synapse=0.1)
b_p = nengo.Probe(b, 'decoded_output', synapse=0.1)
inh_p = nengo.Probe(inh, 'output')
with Simulator(m) as sim:
sim.run(1.0)
t = sim.trange()
ideal = np.sin(t)
ideal[t >= 0.5] = 0
plt.plot(t, sim.data[inn_p], label='Input')
plt.plot(t, sim.data[a_p], label='Neuron approx, pstc=0.1')
plt.plot(t, sim.data[b_p], label='Neuron approx of inhib sig, pstc=0.1')
plt.plot(t, sim.data[inh_p], label='Inhib signal')
plt.plot(t, ideal, label='Ideal output')
plt.legend(loc=0, prop={'size': 10})
assert np.allclose(sim.data[a_p][-10:], 0, atol=.1, rtol=.01)
assert np.allclose(sim.data[b_p][-10:], 1, atol=.1, rtol=.01)
def test_ensemble_to_neurons(Simulator, nl_nodirect, plt, seed):
N = 30
m = nengo.Network(seed=seed)
with m:
m.config[nengo.Ensemble].neuron_type = nl_nodirect()
a = nengo.Ensemble(N, dimensions=1)
b = nengo.Ensemble(N, dimensions=1)
inn = nengo.Node(output=np.sin)
inh = nengo.Node(piecewise({0: 0, 0.5: 1}))
nengo.Connection(inn, a)
nengo.Connection(inh, b)
nengo.Connection(b, a.neurons, transform=[[-2.5]] * N)
inn_p = nengo.Probe(inn, 'output')
a_p = nengo.Probe(a, 'decoded_output', synapse=0.1)
b_p = nengo.Probe(b, 'decoded_output', synapse=0.1)
inh_p = nengo.Probe(inh, 'output')
sim = Simulator(m)
sim.run(1.0)
t = sim.trange()
ideal = np.sin(t)
ideal[t >= 0.5] = 0
plt.plot(t, sim.data[inn_p], label='Input')
plt.plot(t, sim.data[a_p], label='Neuron approx, pstc=0.1')
plt.plot(t, sim.data[b_p], label='Neuron approx of inhib sig, pstc=0.1')
plt.plot(t, sim.data[inh_p], label='Inhib signal')
plt.plot(t, ideal, label='Ideal output')
plt.legend(loc=0, prop={'size': 10})
assert np.allclose(sim.data[a_p][-10:], 0, atol=.1, rtol=.01)
assert np.allclose(sim.data[b_p][-10:], 1, atol=.1, rtol=.01)
def test_node_to_neurons(Simulator, nl_nodirect):
name = 'node_to_neurons'
N = 30
m = nengo.Model(name, seed=123)
a = nengo.Ensemble(nl_nodirect(N), dimensions=1)
inn = nengo.Node(output=np.sin)
inh = nengo.Node(piecewise({0: 0, 2.5: 1}))
nengo.Connection(inn, a)
nengo.Connection(inh, a.neurons, transform=[[-2.5]]*N)
inn_p = nengo.Probe(inn, 'output')
a_p = nengo.Probe(a, 'decoded_output', filter=0.1)
inh_p = nengo.Probe(inh, 'output')
sim = Simulator(m)
sim.run(5.0)
t = sim.trange()
ideal = np.sin(t)
ideal[t >= 2.5] = 0
with Plotter(Simulator, nl_nodirect) as plt:
plt.plot(t, sim.data(inn_p), label='Input')
plt.plot(t, sim.data(a_p), label='Neuron approx, filter=0.1')
plt.plot(t, sim.data(inh_p), label='Inhib signal')
plt.plot(t, ideal, label='Ideal output')
plt.legend(loc=0, prop={'size': 10})
plt.savefig('test_connection.test_' + name + '.pdf')
plt.close()
assert np.allclose(sim.data(a_p)[-10:], 0, atol=.1, rtol=.01)
def test_integrator(Simulator, plt, seed):
model = nengo.Network(seed=seed)
with model:
inputs = {0: 0, 0.2: 1, 1: 0, 2: -2, 3: 0, 4: 1, 5: 0}
input = nengo.Node(piecewise(inputs))
tau = 0.1
T = nengo.networks.Integrator(tau, n_neurons=100, dimensions=1)
nengo.Connection(input, T.input, synapse=tau)
A = nengo.Ensemble(100, dimensions=1)
nengo.Connection(A, A, synapse=tau)
nengo.Connection(input, A, transform=tau, synapse=tau)
input_p = nengo.Probe(input, sample_every=0.01)
A_p = nengo.Probe(A, synapse=0.01, sample_every=0.01)
T_p = nengo.Probe(T.ensemble, synapse=0.01, sample_every=0.01)
sim = Simulator(model)
sim.run(6.0)
t = sim.trange(dt=0.01)
plt.plot(t, sim.data[A_p], label='Manual')
plt.plot(t, sim.data[T_p], label='Template')
plt.plot(t, sim.data[input_p], 'k', label='Input')
plt.legend(loc='best')
assert rmse(sim.data[A_p], sim.data[T_p]) < 0.1
def test_integrator(Simulator, nl):
model = nengo.Model('Integrator')
inputs = {0: 0, 0.2: 1, 1: 0, 2: -2, 3: 0, 4: 1, 5: 0}
input = nengo.Node(piecewise(inputs))
tau = 0.1
T = nengo.networks.Integrator(tau, neurons=nl(100), dimensions=1)
nengo.Connection(input, T.input, filter=tau)
A = nengo.Ensemble(nl(100), dimensions=1)
nengo.Connection(A, A, filter=tau)
nengo.Connection(input, A, transform=tau, filter=tau)
input_p = nengo.Probe(input, 'output')
A_p = nengo.Probe(A, 'decoded_output', filter=0.01)
T_p = nengo.Probe(T.ensemble, 'decoded_output', filter=0.01)
sim = Simulator(model, dt=0.001)
sim.run(6.0)
with Plotter(Simulator, nl) as plt:
t = sim.trange()
plt.plot(t, sim.data(A_p), label='Manual')
plt.plot(t, sim.data(T_p), label='Template')
plt.plot(t, sim.data(input_p), 'k', label='Input')
plt.legend(loc=0)
plt.savefig('test_integrator.test_integrator.pdf')
plt.close()
assert rmse(sim.data(A_p), sim.data(T_p)) < 0.2
def test_oscillator(Simulator, plt, seed):
model = nengo.Network(seed=seed)
with model:
inputs = {0: [1, 0], 0.5: [0, 0]}
input = nengo.Node(piecewise(inputs), label='Input')
tau = 0.1
freq = 5
T = nengo.networks.Oscillator(tau, freq, n_neurons=100)
nengo.Connection(input, T.input)
A = nengo.Ensemble(100, dimensions=2)
nengo.Connection(A,
A,
synapse=tau,
transform=[[1, -freq * tau], [freq * tau, 1]])
nengo.Connection(input, A)
in_probe = nengo.Probe(input, sample_every=0.01)
A_probe = nengo.Probe(A, synapse=0.01, sample_every=0.01)
T_probe = nengo.Probe(T.ensemble, synapse=0.01, sample_every=0.01)
with Simulator(model) as sim:
sim.run(3.0)
t = sim.trange(dt=0.01)
plt.plot(t, sim.data[A_probe], label='Manual')
plt.plot(t, sim.data[T_probe], label='Template')
plt.plot(t, sim.data[in_probe], 'k', label='Input')
plt.legend(loc='best')
assert rmse(sim.data[A_probe], sim.data[T_probe]) < 0.2
def test_integrator(Simulator, plt, seed):
model = nengo.Network(seed=seed)
with model:
inputs = {0: 0, 0.2: 1, 1: 0, 2: -2, 3: 0, 4: 1, 5: 0}
input = nengo.Node(piecewise(inputs))
tau = 0.1
T = nengo.networks.Integrator(tau, n_neurons=100, dimensions=1)
nengo.Connection(input, T.input, synapse=tau)
A = nengo.Ensemble(100, dimensions=1)
nengo.Connection(A, A, synapse=tau)
nengo.Connection(input, A, transform=tau, synapse=tau)
input_p = nengo.Probe(input, sample_every=0.01)
A_p = nengo.Probe(A, synapse=0.01, sample_every=0.01)
T_p = nengo.Probe(T.ensemble, synapse=0.01, sample_every=0.01)
sim = Simulator(model)
sim.run(6.0)
t = sim.trange(dt=0.01)
plt.plot(t, sim.data[A_p], label='Manual')
plt.plot(t, sim.data[T_p], label='Template')
plt.plot(t, sim.data[input_p], 'k', label='Input')
plt.legend(loc='best')
assert rmse(sim.data[A_p], sim.data[T_p]) < 0.1
def test_oscillator(Simulator, plt, seed):
model = nengo.Network(seed=seed)
with model:
inputs = {0: [1, 0], 0.5: [0, 0]}
input = nengo.Node(piecewise(inputs), label='Input')
tau = 0.1
freq = 5
T = nengo.networks.Oscillator(tau, freq, n_neurons=100)
nengo.Connection(input, T.input)
A = nengo.Ensemble(100, dimensions=2)
nengo.Connection(A, A, synapse=tau,
transform=[[1, -freq*tau], [freq*tau, 1]])
nengo.Connection(input, A)
in_probe = nengo.Probe(input, sample_every=0.01)
A_probe = nengo.Probe(A, synapse=0.01, sample_every=0.01)
T_probe = nengo.Probe(T.ensemble, synapse=0.01, sample_every=0.01)
sim = Simulator(model)
sim.run(3.0)
t = sim.trange(dt=0.01)
plt.plot(t, sim.data[A_probe], label='Manual')
plt.plot(t, sim.data[T_probe], label='Template')
plt.plot(t, sim.data[in_probe], 'k', label='Input')
plt.legend(loc='best')
assert rmse(sim.data[A_probe], sim.data[T_probe]) < 0.2
def test_oscillator(Simulator, nl):
model = nengo.Network(label='Oscillator', seed=789)
with model:
inputs = {0: [1, 0], 0.5: [0, 0]}
input = nengo.Node(piecewise(inputs), label='Input')
tau = 0.1
freq = 5
T = nengo.networks.Oscillator(
tau, freq, label="Oscillator", neurons=nl(100))
nengo.Connection(input, T.input)
A = nengo.Ensemble(nl(100), label='A', dimensions=2)
nengo.Connection(A, A, synapse=tau,
transform=[[1, -freq*tau], [freq*tau, 1]])
nengo.Connection(input, A)
in_probe = nengo.Probe(input, "output")
A_probe = nengo.Probe(A, "decoded_output", synapse=0.01)
T_probe = nengo.Probe(T.ensemble, "decoded_output", synapse=0.01)
sim = Simulator(model)
sim.run(3.0)
with Plotter(Simulator, nl) as plt:
t = sim.trange()
plt.plot(t, sim.data[A_probe], label='Manual')
plt.plot(t, sim.data[T_probe], label='Template')
plt.plot(t, sim.data[in_probe], 'k', label='Input')
plt.legend(loc=0)
plt.savefig('test_oscillator.test_oscillator.pdf')
plt.close()
assert rmse(sim.data[A_probe], sim.data[T_probe]) < 0.3
def test_function():
f = piecewise({0: np.sin, 0.5: np.cos})
assert np.allclose(f(0), [np.sin(0)])
assert np.allclose(f(0.25), [np.sin(0.25)])
assert np.allclose(f(0.4999), [np.sin(0.4999)])
assert np.allclose(f(0.5), [np.cos(0.5)])
assert np.allclose(f(0.75), [np.cos(0.75)])
assert np.allclose(f(1.0), [np.cos(1.0)])
def test_function():
f = piecewise({0: np.sin, 0.5: np.cos})
assert np.allclose(f(0), [np.sin(0)])
assert np.allclose(f(0.25), [np.sin(0.25)])
assert np.allclose(f(0.4999), [np.sin(0.4999)])
assert np.allclose(f(0.5), [np.cos(0.5)])
assert np.allclose(f(0.75), [np.cos(0.75)])
assert np.allclose(f(1.0), [np.cos(1.0)])
def test_lists():
f = piecewise({0.5: [1, 0], 1.0: [0, 1]})
assert np.allclose(f(-10), [0, 0])
assert np.allclose(f(0), [0, 0])
assert np.allclose(f(0.25), [0, 0])
assert np.allclose(f(0.5), [1, 0])
assert np.allclose(f(0.75), [1, 0])
assert np.allclose(f(1.0), [0, 1])
assert np.allclose(f(1.5), [0, 1])
assert np.allclose(f(100), [0, 1])
def test_basic():
f = piecewise({0.5: 1, 1.0: 0})
assert np.allclose(f(-10), [0])
assert np.allclose(f(0), [0])
assert np.allclose(f(0.25), [0])
assert np.allclose(f(0.5), [1])
assert np.allclose(f(0.75), [1])
assert np.allclose(f(1.0), [0])
assert np.allclose(f(1.5), [0])
assert np.allclose(f(100), [0])
def test_lists():
f = piecewise({0.5: [1, 0], 1.0: [0, 1]})
assert np.allclose(f(-10), [0, 0])
assert np.allclose(f(0), [0, 0])
assert np.allclose(f(0.25), [0, 0])
assert np.allclose(f(0.5), [1, 0])
assert np.allclose(f(0.75), [1, 0])
assert np.allclose(f(1.0), [0, 1])
assert np.allclose(f(1.5), [0, 1])
assert np.allclose(f(100), [0, 1])
def test_basic():
f = piecewise({0.5: 1, 1.0: 0})
assert np.allclose(f(-10), [0])
assert np.allclose(f(0), [0])
assert np.allclose(f(0.25), [0])
assert np.allclose(f(0.5), [1])
assert np.allclose(f(0.75), [1])
assert np.allclose(f(1.0), [0])
assert np.allclose(f(1.5), [0])
assert np.allclose(f(100), [0])
def test_integrators(net):
with net:
piecewise_f = piecewise({0: 0, 0.2: 0.5, 1: 0, 2: -1, 3: 0, 4: 1, 5: 0})
piecewise_inp = nengo.Node(piecewise_f)
nengo.Connection(piecewise_inp, net.pre_integrator.input)
input_probe = nengo.Probe(piecewise_inp)
pre_probe = nengo.Probe(net.pre_integrator.ensemble, synapse=0.01)
post_probe = nengo.Probe(net.post_integrator.ensemble, synapse=0.01)
with nengo.Simulator(net) as sim:
sim.run(6)
plt.plot(sim.trange(), sim.data[input_probe], color='k')
plt.plot(sim.trange(), sim.data[pre_probe], color='b')
plt.plot(sim.trange(), sim.data[post_probe], color='g')
def test_function_list():
def func1(t):
return t, t ** 2, t ** 3
def func2(t):
return t ** 4, t ** 5, t ** 6
f = piecewise({0: func1, 0.5: func2})
assert np.allclose(f(0), func1(0))
assert np.allclose(f(0.25), func1(0.25))
assert np.allclose(f(0.4999), func1(0.4999))
assert np.allclose(f(0.5), func2(0.5))
assert np.allclose(f(0.75), func2(0.75))
assert np.allclose(f(1.0), func2(1.0))
def test_function_list():
def func1(t):
return t, t**2, t**3
def func2(t):
return t**4, t**5, t**6
f = piecewise({0: func1, 0.5: func2})
assert np.allclose(f(0), func1(0))
assert np.allclose(f(0.25), func1(0.25))
assert np.allclose(f(0.4999), func1(0.4999))
assert np.allclose(f(0.5), func2(0.5))
assert np.allclose(f(0.75), func2(0.75))
assert np.allclose(f(1.0), func2(1.0))
def test_oscillator(Simulator, nl):
model = nengo.Network(label='Oscillator', seed=789)
with model:
model.config[nengo.Ensemble].neuron_type = nl()
inputs = {0: [1, 0], 0.5: [0, 0]}
input = nengo.Node(piecewise(inputs), label='Input')
tau = 0.1
freq = 5
T = nengo.networks.Oscillator(tau,
freq,
label="Oscillator",
n_neurons=100)
nengo.Connection(input, T.input)
A = nengo.Ensemble(100, dimensions=2)
nengo.Connection(A,
A,
synapse=tau,
transform=[[1, -freq * tau], [freq * tau, 1]])
nengo.Connection(input, A)
in_probe = nengo.Probe(input)
A_probe = nengo.Probe(A, synapse=0.01)
T_probe = nengo.Probe(T.ensemble, synapse=0.01)
sim = Simulator(model)
sim.run(3.0)
with Plotter(Simulator, nl) as plt:
t = sim.trange()
plt.plot(t, sim.data[A_probe], label='Manual')
plt.plot(t, sim.data[T_probe], label='Template')
plt.plot(t, sim.data[in_probe], 'k', label='Input')
plt.legend(loc=0)
plt.savefig('test_oscillator.test_oscillator.pdf')
plt.close()
assert rmse(sim.data[A_probe], sim.data[T_probe]) < 0.3
def test_invalid_length():
with pytest.raises(Exception):
f = piecewise({0.5: [1, 0], 1.0: [1, 0, 0]})
assert f
def test_invalid_key():
with pytest.raises(TypeError):
f = piecewise({0.5: 1, 1: 0, 'a': 0.2})
assert f
def test_controlledoscillator(Simulator, plt, rng, seed, outfile):
f_max = 2
T = 2 # time to hold each input for
stims = np.array([1, 0.5, 0, -0.5, -1]) # control signal
tau = 0.1
with nengo.Network(seed=seed) as model:
state = nengo.Ensemble(n_neurons=500, dimensions=3, radius=1.7)
def feedback(x):
x0, x1, f = x
w = f * f_max * 2 * np.pi
return x0 + w * tau * x1, x1 - w * tau * x0
nengo.Connection(state, state[:2], function=feedback, synapse=tau)
freq = nengo.Ensemble(n_neurons=100, dimensions=1)
nengo.Connection(freq, state[2], synapse=tau)
kick = nengo.Node(lambda t: 1 if t < 0.08 else 0)
nengo.Connection(kick, state[0])
control = piecewise({i * T: stim for i, stim in enumerate(stims)})
freq_control = nengo.Node(control)
nengo.Connection(freq_control, freq)
p_state = nengo.Probe(state, synapse=0.03)
if 'spinnaker' in Simulator.__module__:
nengo_spinnaker.add_spinnaker_params(model.config)
model.config[kick].function_of_time = True
model.config[freq_control].function_of_time = True
sim = Simulator(model)
sim.run(len(stims) * T)
data = sim.data[p_state][:, 1]
ideal_freqs = f_max * stims # target frequencies
dt = 0.001
steps = int(T / dt)
freqs = np.fft.fftfreq(steps, d=dt)
# compute fft for each input
data.shape = len(stims), steps
fft = np.fft.fft(data, axis=1)
# compute ideal fft for each input
ideal_data = np.zeros_like(data)
for i in range(len(stims)):
ideal_data[i] = np.cos(2 * np.pi
* ideal_freqs[i]
* np.arange(steps) * dt)
ideal_fft = np.fft.fft(ideal_data, axis=1)
# only consider the magnitude
fft = np.abs(fft)
ideal_fft = np.abs(ideal_fft)
# compute the normalized dot product between the actual and ideal ffts
score = np.zeros(len(stims))
for i in range(len(stims)):
score[i] = np.dot(fft[i] / np.linalg.norm(fft[i]),
ideal_fft[i] / np.linalg.norm(ideal_fft[i]))
outfile.write('"n_neurons": %d,\n' % sum(
e.n_neurons for e in model.all_ensembles))
outfile.write('"simtime": %f,\n' % (len(stims) * T))
outfile.write('"score": %f,\n' % np.mean(score))
figsize = (onecolumn, 4.0) if horizontal else (onecolumn * 2, 4.0)
setup(figsize=figsize)
lines = []
if type(plt).__name__ != 'Mock':
for i, y in enumerate(np.fft.fftshift(fft, axes=1)):
lines.append(plt.stem(np.fft.fftshift(freqs), y))
marker, stem, base = lines[-1]
marker.set_color(colors[i])
marker.set_markersize(10.0)
for s in stem:
s.set_color(colors[i])
s.set_linewidth(1.0)
base.set_visible(False)
plt.xlim(-f_max * 2, f_max * 2)
plt.xlabel('Frequency (Hz)')
plt.ylabel('Power of decoded value')
plt.legend(lines, ['%gHz' % f for f in ideal_freqs],
loc='best', prop={'size': 8})
sns.despine()
plt.saveas = 'results-3.svg'
if hasattr(sim, 'close'):
sim.close()
def test_invalid_function_length():
with pytest.raises(ValidationError):
f = piecewise({0.5: 0, 1.0: lambda t: [t, t**2]})
assert f
def test_invalid_key():
with pytest.raises(ValidationError):
f = piecewise({0.5: 1, 1: 0, 'a': 0.2})
assert f
from nengo.utils.functions import piecewise
model = nengo.Network(label="Inhibitory Gating")
n_neurons = 30
with model:
A = nengo.Ensemble(n_neurons, dimensions=1, label="A")
B = nengo.Ensemble(n_neurons, dimensions=1, label="B")
C = nengo.Ensemble(n_neurons, dimensions=1, label="C")
sin = nengo.Node(np.sin, label="sin")
inhib = nengo.Node(piecewise({
0: 0,
2.5: 1,
5: 0,
7.5: 1,
10: 0,
12.5: 1
}),
label="inhibition")
nengo.Connection(sin, A)
nengo.Connection(sin, B)
nengo.Connection(inhib, A.neurons, transform=[[-2.5]] * n_neurons)
nengo.Connection(inhib, C)
nengo.Connection(C, B.neurons, transform=[[-2.5]] * n_neurons)
sin_probe = nengo.Probe(sin)
inhib_probe = nengo.Probe(inhib)
A_probe = nengo.Probe(A, synapse=0.01)
B_probe = nengo.Probe(B, synapse=0.01)
import nengo
import numpy as np
from nengo.utils.functions import piecewise
model = nengo.Network(label="Inhibitory Gating")
n_neurons = 30
with model:
A = nengo.Ensemble(n_neurons, dimensions=1, label="A")
B = nengo.Ensemble(n_neurons, dimensions=1, label="B")
C = nengo.Ensemble(n_neurons, dimensions=1, label="C")
sin = nengo.Node(np.sin, label="sin")
inhib = nengo.Node(
piecewise({0: 0, 2.5: 1, 5: 0, 7.5: 1, 10: 0, 12.5: 1}),
label="inhibition")
nengo.Connection(sin, A)
nengo.Connection(sin, B)
nengo.Connection(inhib, A.neurons, transform=[[-2.5]] * n_neurons)
nengo.Connection(inhib, C)
nengo.Connection(C, B.neurons, transform=[[-2.5]] * n_neurons)
sin_probe = nengo.Probe(sin)
inhib_probe = nengo.Probe(inhib)
A_probe = nengo.Probe(A, synapse=0.01)
B_probe = nengo.Probe(B, synapse=0.01)
C_probe = nengo.Probe(C, synapse=0.01)
def test_invalid_length():
with pytest.raises(Exception):
f = piecewise({0.5: [1, 0], 1.0: [1, 0, 0]})
assert f
from nengo.utils.functions import piecewise
DURATION = 5.0
def product(x):
return x[0] * x[1]
def square(x):
return x[0] * x[0]
model = nengo.Network(label="sum")
with model:
input0 = nengo.Node(piecewise({0: -0.75, 1.25: 0.50, 2.5: -0.75, 3.75: 0}))
input1 = nengo.Node(piecewise({0: 1.00, 1.25: 0.25, 2.5: -0.25, 3.75: 0}))
ensemble0 = nengo.Ensemble(100, dimensions=1, radius=1)
ensemble1 = nengo.Ensemble(100, dimensions=1, radius=1)
ensemble_inp_2d = nengo.Ensemble(100, dimensions=2, radius=2)
ensemble_prod = nengo.Ensemble(100, dimensions=1, radius=1)
ensemble_sqr = nengo.Ensemble(100, dimensions=1, radius=1)
nengo.Connection(input0, ensemble0)
nengo.Connection(input1, ensemble1)
nengo.Connection(ensemble0, ensemble_inp_2d[0])
nengo.Connection(ensemble1, ensemble_inp_2d[1])
nengo.Connection(ensemble_inp_2d, ensemble_prod, function=product)
nengo.Connection(ensemble0, ensemble_sqr, function=square)
input0_probe = nengo.Probe(input0)
input1_probe = nengo.Probe(input1)
ensemble0_probe = nengo.Probe(ensemble0, synapse=0.01)
import nengo
tau = 0.1
model = nengo.Model('Integrator')
integrator = nengo.networks.Integrator(tau,
neurons=nengo.LIF(100),
dimensions=1)
from nengo.utils.functions import piecewise
input = nengo.Node(piecewise({0: 0, 0.2: 1, 1: 0, 2: -2, 3: 0, 4: 1, 5: 0}))
nengo.Connection(input, integrator.input, filter=tau)
# (or any other linear system).
# Create the model object
import nengo
from nengo.utils.functions import piecewise
import matplotlib.pyplot as plt
import numpy as np
model = nengo.Network(label='Oscillator')
with model:
# Create the ensemble for the oscillator
neurons = nengo.Ensemble(200, dimensions=2, label="neurons")
# Create an input signal
input = nengo.Node(piecewise({0: [1, 0], 0.1: [0, 0]}), label="input")
# Connect the input signal to the neural ensemble
nengo.Connection(input, neurons)
# Create the feedback connection
nengo.Connection(neurons, neurons, transform=[[1, 1], [-1, 1]], synapse=0.1)
input_probe = nengo.Probe(input, 'output')
neuron_probe = nengo.Probe(neurons, 'decoded_output', synapse=0.1)
# start the simulator
sim = nengo.Simulator(model)
# dynamic plotting
# The ensemble for the oscillator
oscillator = nengo.Ensemble(500, dimensions=3, radius=1.7, label="oscillator")
# The feedback connection
def feedback(x):
x0, x1, w = x # These are the three variables stored in the ensemble
return x0 + w*w_max*tau*x1, x1 - w*w_max*tau*x0, 0
nengo.Connection(oscillator, oscillator, function=feedback, synapse=tau)
# The ensemble for controlling the speed of oscillation
frequency = nengo.Ensemble(100, dimensions=1, label="frequency")
nengo.Connection(frequency, oscillator[2])
# We need a quick input at the beginning to start the oscillator
initial = nengo.Node(piecewise({0: [1, 0, 0], 0.15: [0, 0, 0]}), label="input")
nengo.Connection(initial, oscillator)
# Vary the speed over time
input_frequency = nengo.Node(
piecewise({0: 1, 1: 0.5, 2: 0, 3: -0.5, 4: -1}), label="frequency control")
nengo.Connection(input_frequency, frequency)
# Indicate which values to record
oscillator_probe = nengo.Probe(oscillator, synapse=0.03)
import nengo_gui
def test_invalid_function_length():
with pytest.raises(Exception):
f = piecewise({0.5: 0, 1.0: lambda t: [t, t ** 2]})
assert f
# more directly to the differential equation used to describe an integrator:
# $\dot{x} = \mathrm{Ax}(t) + \mathrm{Bu}(t)$ The control in this circuit is
# A in that equation. This is also the controlled integrator described in the
# book How to build a brain.
import nengo
from nengo.utils.functions import piecewise
model = nengo.Network(label='Controlled Integrator 2')
with model:
# Make a population with 225 LIF neurons representing a 2
# dimensional signal, with a larger radius to accommodate large inputs
A = nengo.Ensemble(225, dimensions=2, radius=1.5, label="A")
# Create a piecewise step function for input
input_func = piecewise(
{0.2: 5, 0.3: 0, 0.44: -10, 0.54: 0, 0.8: 5, 0.9: 0})
inp = nengo.Node(output=input_func, label="input")
# Connect the Input signal to ensemble A.
tau = 0.1
nengo.Connection(inp, A, transform=[[tau], [0]], synapse=0.1)
# Another piecewise function that changes half way through the run
control_func = piecewise({0: 0, 0.6: -0.5})
control = nengo.Node(output=control_func, label="control")
# Connect the "Control" signal to the second of A's two input channels
nengo.Connection(control, A[1], synapse=0.005)
# Note the changes from the previous example to the function being defined.
nengo.Connection(A, A[0],
return -x[0] * x[1]
# INPUTS / OUTPUTS #
# Amy
stim_amyg = nengo.Node([1])
# OFC
possible_stim = np.vstack(
(np.linspace(0.1, 0.9, num=7), np.linspace(0.05, 0.6, num=7) * (-1)))
all_stim = input_stim(possible_stim, n_trials) # indicate number of trials
cur_dic = stim_time(all_stim, len_stim, len_pause,
len_fix) # (len_stim, len_pause,len_fix)
# mod((length of stim),(number of features plus 1))!=0
cur_dic = collections.OrderedDict(sorted(cur_dic.items()))
stim_ofc = nengo.Node(piecewise(cur_dic))
# ENSEMBLES #
# AMYG
amyg = nengo.Ensemble(N,
1,
radius=brad,
max_rates=get_maxrates(N, 100, 100),
neuron_type=neurontype)
# OFC
ofc = nengo.Ensemble(N,
2,
max_rates=get_maxrates(N, 100, 100),
radius=brad,
neuron_type=neurontype)
c1 = scipy.special.binom(n, k)
c2 = scipy.special.binom((n+k-1)/2, n)
coeffs.append(c1 * c2)
def L(x):
accumulator = np.zeros(x.shape)
argument = np.ones(x.shape)
for k in range(n+1):
accumulator += np.multiply(argument, coeffs[k])
argument = np.multiply(argument, x)
return 2.0**n * accumulator
return L
model = nengo.Network(label='Integrator')
with model:
A = nengo.Ensemble(100, dimensions=1)
input = nengo.Node(piecewise({0:0, 0.2:1, 1:0, 2:-2, 3:0, 4:1, 5:0}))
tau = 0.1
conn_recurrent = nengo.Connection(A, A, transform=[[1]], synapse=tau)
conn_input = nengo.Connection(input, A, transform=[[tau]], synapse=tau)
input_probe = nengo.Probe(input)
A_probe = nengo.Probe(A, synapse=0.01)
sim = nengo.Simulator(model)
# find 1-D principal components and plot
eval_points_in = np.linspace(-2.0, 2.0, 50)
eval_points_in = np.ndarray(shape=(50,1), buffer=eval_points_in)
eval_points, activities = tuning_curves(A, sim, eval_points_in)
#plt.figure()
#plt.title("Tuning curves")
#plt.plot(eval_points, activities)
pre_ensemble = nengo.Ensemble(100, dimensions=1)
nengo.Connection(pre_ensemble, pre_ensemble, synapse=0.1)
nengo.Connection(pre_input, pre_ensemble, synapse=None, transform=0.1)
with nengo.Network() as post_integrator:
post_input = nengo.Node(size_in=1)
post_ensemble = nengo.Ensemble(100, dimensions=1)
nengo.Connection(post_ensemble, post_ensemble, synapse=0.1)
nengo.Connection(post_input, post_ensemble, synapse=None, transform=0.1)
nengo.Connection(pre_ensemble, post_input)
# In[ ]:
# Test the integrators by giving piecewise input and plotting
with net:
piecewise_f = piecewise({0: 0, 0.2: 0.5, 1: 0, 2: -1, 3: 0, 4: 1, 5: 0})
piecewise_inp = nengo.Node(piecewise_f)
nengo.Connection(piecewise_inp, pre_input)
input_probe = nengo.Probe(piecewise_inp)
pre_probe = nengo.Probe(pre_ensemble, synapse=0.01)
post_probe = nengo.Probe(post_ensemble, synapse=0.01)
with nengo.Simulator(net) as sim:
sim.run(6)
plt.plot(sim.trange(), sim.data[input_probe], color='k', label="input")
plt.plot(sim.trange(), sim.data[pre_probe], color='b', label="pre integrator")
plt.plot(sim.trange(), sim.data[post_probe], color='g', label="post integrator")
plt.legend(loc='best');
# Note that the `with` statements
# are not just cosmetic;
# template which can also be used to quickly construct a harmonic oscillator
# (or any other linear system).
# Create the model object
import nengo
from nengo.utils.functions import piecewise
import matplotlib.pyplot as plt
import numpy as np
model = nengo.Network(label='Oscillator')
with model:
# Create the ensemble for the oscillator
neurons = nengo.Ensemble(200, dimensions=2, label="neurons")
# Create an input signal
input = nengo.Node(piecewise({0: [1, 0], 0.1: [0, 0]}), label="input")
# Connect the input signal to the neural ensemble
nengo.Connection(input, neurons)
# Create the feedback connection
nengo.Connection(neurons,
neurons,
transform=[[1, 1], [-1, 1]],
synapse=0.1)
input_probe = nengo.Probe(input, 'output')
neuron_probe = nengo.Probe(neurons, 'decoded_output', synapse=0.1)
# start the simulator
sim = nengo.Simulator(model)
def test_invalid_length():
with pytest.raises(ValidationError):
f = piecewise({0.5: [1, 0], 1.0: [1, 0, 0]})
assert f
manual = nengo.Node([0, 0])
#### actions / rewards
actions = nengo.Ensemble(100, 2, radius=1.4) # which action to choose
errors = nengo.networks.EnsembleArray(n_neurons=50, n_ensembles=2)
act_times = {0: 1}
pause = 0.5
choice = 0.2
time = 0
for i in range(500):
act_times[time] = 1
time += pause
act_times[time] = 0
time += choice
act = nengo.Node(piecewise(act_times))
nengo.Connection(act,
actions.neurons,
transform=-2 * np.ones((actions.n_neurons, 1)))
nengo.Connection(actions, reward)
nengo.Connection(reward, errors.input, transform=-1)
nengo.Connection(manual, actions)
#### input to basal ganglia
# random_thoughts = nengo.Node(np.sin)
state = nengo.Ensemble(100, 2, radius=2)
#state_integrator = nengo.Ensemble(100,1,radius=2)
norm_state = nengo.Ensemble(100, 2, radius=2)
# nengo.Connection(random_thoughts, state)
nengo.Connection(state, norm_state, function=normalize)
from __future__ import division
from nengo.utils.functions import piecewise
import numpy as np
import nengo
import matplotlib.pyplot as plt
import raphan_matrices as rmat
# MODEL PARAMETERS
# =====
TAU_RECUR = 0.1
input_func = input_func = piecewise({0: 0, 0.2: 5, 0.3: 0, 0.44: -10, 0.54: 0, 0.8: 5, 0.9: 0})
control_func = piecewise({0: 1, 0.6: 0.5}) # function to define integrator behaviour
model = nengo.Network(label='1dinteg')
with model:
A = nengo.Ensemble(200, dimensions=2, radius=1.5)
inp = nengo.Node(input_func)
control = nengo.Node(output=control_func)
# wire the stimulus input
nengo.Connection(inp, A, transform=[[TAU_RECUR], [0]], synapse=TAU_RECUR)
# wire the control quality input
nengo.Connection(control, A[1], synapse=0.005)
# set up the recurrent input
nengo.Connection(A, A[0],
function = lambda x: x[0] * x[1],
synapse=TAU_RECUR)
import nengo
tau = 0.1 # Post-synaptic time constant for feedback\n",
w_max = 10 # Maximum frequency is w_max/(2*pi)\n",
model = nengo.Model('Controlled Oscillator')
oscillator = nengo.Ensemble(nengo.LIF(500), dimensions=3, radius=1.7)
def feedback(x):
x0, x1, w = x # These are the three variables stored in the ensemble\n",
return x0 + w * w_max * tau * x1, x1 - w * w_max * tau * x0, 0
nengo.Connection(oscillator, oscillator, function=feedback, filter=tau)
frequency = nengo.Ensemble(nengo.LIF(100), dimensions=1)
nengo.Connection(frequency, oscillator, transform=[[0], [0], [1]])
from nengo.utils.functions import piecewise
initial = nengo.Node(piecewise({0: [1, 0, 0], 0.15: [0, 0, 0]}))
nengo.Connection(initial, oscillator)
input_frequency = nengo.Node(piecewise({0: 1, 1: 0.5, 2: 0, 3: -0.5, 4: -1}))
nengo.Connection(input_frequency, frequency)
import nengo
tau = 0.1 # Post-synaptic time constant for feedback\n",
w_max = 10 # Maximum frequency is w_max/(2*pi)\n",
model = nengo.Model('Controlled Oscillator')
oscillator = nengo.Ensemble(nengo.LIF(500), dimensions=3, radius=1.7)
def feedback(x):
x0, x1, w = x # These are the three variables stored in the ensemble\n",
return x0 + w*w_max*tau*x1, x1 - w*w_max*tau*x0, 0
nengo.Connection(oscillator, oscillator, function=feedback, filter=tau)
frequency = nengo.Ensemble(nengo.LIF(100), dimensions=1)
nengo.Connection(frequency, oscillator, transform=[[0], [0], [1]])
from nengo.utils.functions import piecewise
initial = nengo.Node(piecewise({0: [1, 0, 0], 0.15: [0, 0, 0]}))
nengo.Connection(initial, oscillator)
input_frequency = nengo.Node(piecewise({0: 1, 1: 0.5, 2: 0, 3: -0.5, 4: -1}))
nengo.Connection(input_frequency, frequency)
import nengo
model = nengo.Model("Inhibitory Gating")
n_neurons = 30
A = nengo.Ensemble(nengo.LIF(n_neurons), dimensions=1)
B = nengo.Ensemble(nengo.LIF(n_neurons), dimensions=1)
C = nengo.Ensemble(nengo.LIF(n_neurons), dimensions=1)
import numpy as np
from nengo.utils.functions import piecewise
sin = nengo.Node(output=np.sin)
inhib = nengo.Node(output=piecewise({
0: 0,
2.5: 1,
5: 0,
7.5: 1,
10: 0,
12.5: 1
}))
nengo.Connection(sin, A)
nengo.Connection(sin, B)
nengo.Connection(inhib, A.neurons, transform=[[-2.5]] * n_neurons)
nengo.Connection(inhib, C)
nengo.Connection(C, B.neurons, transform=[[-2.5]] * n_neurons)
import nengo
model = nengo.Model('Oscillator')
neurons = nengo.Ensemble(nengo.LIF(200), dimensions=2)
from nengo.utils.functions import piecewise
input = nengo.Node(output=piecewise({0: [1, 0], 0.1: [0, 0]}))
nengo.Connection(input, neurons)
nengo.Connection(neurons, neurons, transform=[[1, 1], [-1, 1]], filter=0.1)
# This next two lines make all of the encoders in the Combined population point at the
# corners of the cube. This improves the quality of the computation.
from nengo.dists import Choice
# Comment out the line below for 'normal' encoders
combined.encoders = Choice([[1, 1], [-1, 1], [1, -1], [-1, -1]])
# ## Step 2: Provide input to the model
# We will use two varying scalar values for the two input signals that drive activity in ensembles A and B.
# In[ ]:
from nengo.utils.functions import piecewise
with model:
# Create a piecewise step function for input
inputA = nengo.Node(piecewise({0: 0, 2.5: 10, 4: -10}))
inputB = nengo.Node(piecewise({0: 10, 1.5: 2, 3: 0, 4.5: 2}))
correct_ans = piecewise({0: 0, 1.5: 0, 2.5: 20, 3: 0, 4: 0, 4.5: -20})
# ## Step 3: Connect the elements of the model
# In[ ]:
with model:
# Connect the input nodes to the appropriate ensembles
nengo.Connection(inputA, A)
nengo.Connection(inputB, B)
# Connect input ensembles A and B to the 2D combined ensemble
nengo.Connection(A, combined[0])
from nengo.utils.functions import piecewise
__author__ = 'bogdanp'
import nengo
import nengo.spa as spa
model = nengo.Network("Oscillator network")
with model:
input = nengo.Node(piecewise({0: [1, 0], 0.1: [0, 0]}))
osc = nengo.networks.Oscillator(1, 1, 100)
nengo.Connection(input, osc.input)
import nengo
model = nengo.Model('Integrator')
A = nengo.Ensemble(nengo.LIF(100), dimensions=1, label='Integrator')
from nengo.utils.functions import piecewise
input = nengo.Node(piecewise({0: 0, 0.2: 1, 1: 0, 2: -2, 3: 0, 4: 1, 5: 0}), label='Piecewise input')
tau = 0.1
nengo.Connection(A, A, transform=[[1]], filter=tau) # Using a long time constant for stability\n"
nengo.Connection(input, A, transform=[[tau]], filter=tau) # The same time constant as recurrent to make it more 'ideal'"
def test_invalid_key():
with pytest.raises(ValidationError):
f = piecewise({0.5: 1, 1: 0, "a": 0.2})
assert f
def test_invalid_length():
with pytest.raises(ValidationError):
f = piecewise({0.5: [1, 0], 1.0: [1, 0, 0]})
assert f
# controlled integrator. We create a Network, and then we create a population
# of neurons (called an *ensemble*). This population of neurons will
# represent the state of our integrator, and the connections between
# the neurons in the ensemble will define the dynamics of our integrator.
import nengo
from nengo.utils.functions import piecewise
model = nengo.Network(label='Controlled Integrator')
with model:
# Make a population with 225 LIF neurons representing a 2 dimensional
# signal, with a larger radius to accommodate large inputs
A = nengo.Ensemble(225, dimensions=2, radius=1.5, label="A")
# Create a piecewise step function for input
input_func = piecewise(
{0: 0, 0.2: 5, 0.3: 0, 0.44: -10, 0.54: 0, 0.8: 5, 0.9: 0})
# Define an input signal within our model
inp = nengo.Node(input_func, label="input")
# Connect the Input signal to ensemble A.
# The `transform` argument means "connect real-valued signal "Input" to the
# first of the two input channels of A."
tau = 0.1
nengo.Connection(inp, A, transform=[[tau], [0]], synapse=tau)
# Another piecewise step that changes half way through the run
control_func = piecewise({0: 1, 0.6: 0.5})
control = nengo.Node(output=control_func, label="control")
# Connect the "Control" signal to the second of A's two input channels.
import nengo
model = nengo.Model("Inhibitory Gating")
n_neurons = 30
A = nengo.Ensemble(nengo.LIF(n_neurons), dimensions=1)
B = nengo.Ensemble(nengo.LIF(n_neurons), dimensions=1)
C = nengo.Ensemble(nengo.LIF(n_neurons), dimensions=1)
import numpy as np
from nengo.utils.functions import piecewise
sin = nengo.Node(output=np.sin)
inhib = nengo.Node(output=piecewise({0: 0, 2.5: 1, 5: 0, 7.5: 1, 10: 0, 12.5: 1}))
nengo.Connection(sin, A)
nengo.Connection(sin, B)
nengo.Connection(inhib, A.neurons, transform=[[-2.5]] * n_neurons)
nengo.Connection(inhib, C)
nengo.Connection(C, B.neurons, transform=[[-2.5]] * n_neurons)
