def _build(self):
'''Create populations.'''
def pos(idx):
assert idx == 0, 'This population has only one node.'
return (0.5, 0.5)
# Source node is located at (0.5, 0.5) because csa.random2d() can
# only scatter nodes on the unit square.
self._g1 = pos
self._g2 = csa.random2d(self._N)
self._d = csa.euclidMetric2d(self._g1, self._g2)
def _connect(self):
'''Connect populations.'''
g1 = self._geometryFunction(self._ls)
g2 = self._geometryFunction(self._lt)
d = csa.euclidMetric2d(g1, g2)
sigma = self._params['sigma']
cutoff = self._max_dist
cs = csa.cset(
csa.cross([0], xrange(self._N - 1)) *
(csa.random * (csa.gaussian(sigma, cutoff) * d)), 1.0, 1.0)
nest.CGConnect(
nest.GetLeaves(self._ls)[0],
nest.GetLeaves(self._lt)[0], cs, {
'weight': 0,
'delay': 1
})
def csa_topology_example():
# layers have 20x20 neurons and extent 1 x 1
pop1 = topo.CreateLayer({'elements': 'iaf_neuron',
'rows': 20, 'columns': 20})
pop2 = topo.CreateLayer({'elements': 'iaf_neuron',
'rows': 20, 'columns': 20})
# create CSA-style geometry functions and metric
g1 = geometryFunction(pop1)
g2 = geometryFunction(pop2)
d = csa.euclidMetric2d(g1, g2)
# Gaussian connectivity profile, sigma = 0.2, cutoff at 0.5
cs = csa.cset(csa.random * (csa.gaussian(0.2, 0.5) * d), 10000.0, 1.0)
# create connections
nest.CGConnect(pop1, pop2, cs, {"weight": 0, "delay": 1})
# show targets of center neuron
topo.PlotTargets(topo.FindCenterElement(pop1), pop2)
'rows': 20,
'columns': 20
})
pop2 = topo.CreateLayer({
'elements': 'iaf_psc_alpha',
'rows': 20,
'columns': 20
})
"""
For each layer, we create a CSA-style geometry function and a CSA
metric based on them.
"""
g1 = geometryFunction(pop1)
g2 = geometryFunction(pop2)
d = csa.euclidMetric2d(g1, g2)
"""
The connection set ``cs`` describes a Gaussian connectivity profile
with sigma = 0.2 and cutoff at 0.5, and two values (10000.0 and 1.0)
used as weight and delay, respectively.
"""
cs = csa.cset(csa.random * (csa.gaussian(0.2, 0.5) * d), 10000.0, 1.0)
"""
We can now connect the populations using the `CGConnect` function.
It takes the IDs of pre- and postsynaptic neurons (``pop1`` and
``pop2``), the connection set (``cs``) and a dictionary that maps
the parameters weight and delay to positions in the value set
associated with the connection set.
"""
def do_run(plot):
p.setup(timestep=1.0)
cell_params_lif = {
'cm': 0.25,
'i_offset': 0.0,
'tau_m': 20.0,
'tau_refrac': 2.0,
'tau_syn_E': 5.0,
'tau_syn_I': 5.0,
'v_reset': -70.0,
'v_rest': -65.0,
'v_thresh': -40.0
}
n = 13 # 10 # 5
p.set_number_of_neurons_per_core(p.IF_curr_exp, n)
weight_to_spike = 2.0
delay = 5
runtime = 200
# Network
grid = csa.grid2d(n, xScale=1.0 * n, yScale=1.0 * n)
# SpikeInjector
injectionConnection = [(0, 0)]
spikeArray = {'spike_times': [[0]]}
inj_pop = p.Population(1,
p.SpikeSourceArray(**spikeArray),
label='inputSpikes_1')
# grid population
grid_pop = p.Population(n * n,
p.IF_curr_exp(**cell_params_lif),
label='grid_pop')
p.Projection(inj_pop, grid_pop, p.FromListConnector(injectionConnection),
p.StaticSynapse(weight=weight_to_spike, delay=delay))
# Connectors
exc_connector_set = csa.disc(2.5) * csa.euclidMetric2d(grid)
exc_connector = p.CSAConnector(exc_connector_set)
inh_connector_set = csa.disc(1.5) * csa.euclidMetric2d(grid)
inh_connector = p.CSAConnector(inh_connector_set)
# Wire grid
p.Projection(grid_pop, grid_pop, exc_connector,
p.StaticSynapse(weight=2.0, delay=10))
p.Projection(grid_pop, grid_pop, inh_connector,
p.StaticSynapse(weight=0.5, delay=15))
grid_pop.record(['v', 'spikes'])
p.run(runtime)
v = grid_pop.spinnaker_get_data('v')
spikes = grid_pop.spinnaker_get_data('spikes')
if plot:
# original grid
csa.gplot2d(grid, n * n)
# excitatory connector
exc_connector.show_connection_set()
csa.gplotsel2d(grid,
exc_connector_set,
range(n * n),
range(n * n),
N0=n * n)
# inhibitory connector
inh_connector.show_connection_set()
csa.gplotsel2d(grid,
inh_connector_set,
range(n * n),
range(n * n),
N0=n * n)
# Now plot spikes and v
pylab.figure()
pylab.plot([i[1] for i in spikes], [i[0] for i in spikes], "r.")
pylab.xlabel('Time/ms')
pylab.ylabel('spikes')
pylab.title('spikes')
pylab.show()
pylab.figure()
ticks = len(v) // (n * n)
for pos in range(0, n * n):
v_for_neuron = v[pos * ticks:(pos + 1) * ticks]
pylab.plot([i[2] for i in v_for_neuron])
pylab.xlabel('Time/ms')
pylab.ylabel('V')
pylab.title('membrane voltages per neuron')
pylab.show()
p.end()
return v, spikes
We create two layers that have 20x20 neurons of type `iaf_psc_alpha`.
"""
pop1 = topo.CreateLayer({'elements': 'iaf_psc_alpha',
'rows': 20, 'columns': 20})
pop2 = topo.CreateLayer({'elements': 'iaf_psc_alpha',
'rows': 20, 'columns': 20})
"""
For each layer, we create a CSA-style geometry function and a CSA
metric based on them.
"""
g1 = geometryFunction(pop1)
g2 = geometryFunction(pop2)
d = csa.euclidMetric2d(g1, g2)
"""
The connection set ``cs`` describes a Gaussian connectivity profile
with sigma = 0.2 and cutoff at 0.5, and two values (10000.0 and 1.0)
used as weight and delay, respectively.
"""
cs = csa.cset(csa.random * (csa.gaussian(0.2, 0.5) * d), 10000.0, 1.0)
"""
We can now connect the populations using the `CGConnect` function.
It takes the IDs of pre- and postsynaptic neurons (``pop1`` and
``pop2``), the connection set (``cs``) and a dictionary that maps
the parameters weight and delay to positions in the value set
associated with the connection set.
node = setup(timestep=0.025, min_delay=1.0, max_delay=1.0, debug=True, quit_on_end=False)
print "Process with rank %d running on %s" % (node, socket.gethostname())
rng = NumpyRNG(seed=seed, parallel_safe=True)
print "[%d] Creating populations" % node
n_spikes = int(2*tstop*input_rate/1000.0)
spike_times = numpy.add.accumulate(rng.next(n_spikes, 'exponential',
[1000.0/input_rate], mask_local=False))
input_population = Population(10, SpikeSourceArray, {'spike_times': spike_times }, label="input")
output_population = Population(10, IF_curr_exp, cell_params, label="output")
g=csa.grid2d(3)
d=csa.euclidMetric2d(g,g)
connector = CSAConnector(csa.cset(csa.random(0.5), csa.gaussian(0.1,1.0)*d, 1.0))
projection = Projection(input_population, output_population, connector, rng=rng)
file_stem = "Results/simpleRandomNetwork_np%d_%s" % (num_processes(), simulator_name)
projection.saveConnections('%s.conn' % file_stem)
output_population.record_v()
print "[%d] Running simulation" % node
run(tstop)
print "[%d] Writing Vm to disk" % node
output_population.print_v('%s.v' % file_stem)