Creating a counter

General Discussion
2

If you want the function of the node to have a stateful value, you should use a class. Here’s a basic example of a counter that increments when above a threshold.

import nengo

import matplotlib.pyplot as plt

dt = 0.001

class Counter(object):

    def __init__(self):
        self.count = 0

    def state_func(self, t, x):
        if x > 0.8:
            self.count += 1
        
        return self.count


def in_func(t):
    if ((t - dt) % 1) > 0.5:
        return 1
    else:
        return 0

counter = Counter()

with nengo.Network() as model:
    in_nd = nengo.Node(in_func, size_out=1)
    state_nd = nengo.Node(counter.state_func, size_in=1, size_out=1)
    
    nengo.Connection(in_nd, state_nd, synapse=None)

    p_in = nengo.Probe(in_nd)
    p_state = nengo.Probe(state_nd)

with nengo.Simulator(model) as sim:
    sim.run(3.0)

plt.plot(sim.data[p_in])
plt.show()

plt.plot(sim.data[p_state])
plt.show()

To complete your use case, you’re going to need a bit more complex logic in the state_func.