def test_am_basic(Simulator, plt, seed, rng):
"""Basic associative memory test."""
d = 64
vocab = Vocabulary(d, pointer_gen=rng)
vocab.populate("A; B; C; D")
with spa.Network("model", seed=seed) as m:
m.am = ThresholdingAssocMem(
threshold=0.3,
input_vocab=vocab,
mapping=vocab.keys(),
function=filtered_step_fn,
)
spa.sym.A >> m.am
in_p = nengo.Probe(m.am.input)
out_p = nengo.Probe(m.am.output, synapse=0.03)
with Simulator(m) as sim:
sim.run(0.2)
t = sim.trange()
plt.subplot(3, 1, 1)
plt.plot(t, similarity(sim.data[in_p], vocab))
plt.ylabel("Input")
plt.ylim(top=1.1)
plt.subplot(3, 1, 2)
plt.plot(t, similarity(sim.data[out_p], vocab))
plt.plot(t[t > 0.15], np.ones(t.shape)[t > 0.15] * 0.95, c="g", lw=2)
plt.ylabel("Output")
assert_sp_close(t, sim.data[in_p], vocab["A"], skip=0.15, atol=0.05)
assert_sp_close(t, sim.data[out_p], vocab["A"], skip=0.15)
def test_am_wta(Simulator, plt, seed, rng):
"""Test the winner-take-all ability of the associative memory."""
d = 64
vocab = Vocabulary(d, pointer_gen=rng)
vocab.populate("A; B; C; D")
def input_func(t):
if t < 0.2:
return "A + 0.8 * B"
elif t < 0.3:
return "0"
else:
return "0.8 * A + B"
with spa.Network("model", seed=seed) as m:
m.am = WTAAssocMem(
threshold=0.3,
input_vocab=vocab,
mapping=vocab.keys(),
function=filtered_step_fn,
)
m.stimulus = spa.Transcode(input_func, output_vocab=vocab)
m.stimulus >> m.am
in_p = nengo.Probe(m.am.input)
out_p = nengo.Probe(m.am.output, synapse=0.03)
with Simulator(m) as sim:
sim.run(0.5)
t = sim.trange()
more_a = (t > 0.15) & (t < 0.2)
more_b = t > 0.45
plt.subplot(2, 1, 1)
plt.plot(t, similarity(sim.data[in_p], vocab))
plt.ylabel("Input")
plt.ylim(top=1.1)
plt.subplot(2, 1, 2)
plt.plot(t, similarity(sim.data[out_p], vocab))
plt.plot(t[more_a], np.ones(t.shape)[more_a] * 0.9, c="g", lw=2)
plt.plot(t[more_b], np.ones(t.shape)[more_b] * 0.9, c="g", lw=2)
plt.ylabel("Output")
assert_sp_close(t, sim.data[out_p], vocab["A"], skip=0.15, duration=0.05)
assert_sp_close(t, sim.data[out_p], vocab["B"], skip=0.45, duration=0.05)
def test_am_ia(Simulator, plt, seed, rng):
"""Test the winner-take-all ability of the IA memory."""
d = 64
vocab = Vocabulary(d, pointer_gen=rng)
vocab.populate("A; B; C; D")
def input_func(t):
if t < 0.2:
return "A + 0.8 * B"
else:
return "0.6 * A + B"
with spa.Network("model", seed=seed) as m:
m.am = IAAssocMem(input_vocab=vocab, mapping=vocab.keys())
m.stimulus = spa.Transcode(input_func, output_vocab=vocab)
m.reset = nengo.Node(lambda t: 0.2 < t < 0.4)
m.stimulus >> m.am
nengo.Connection(m.reset, m.am.input_reset, synapse=0.1)
in_p = nengo.Probe(m.am.input)
reset_p = nengo.Probe(m.reset)
out_p = nengo.Probe(m.am.output, synapse=0.03)
with nengo.Simulator(m) as sim:
sim.run(0.7)
t = sim.trange()
more_a = (t > 0.15) & (t < 0.2)
more_b = t > 0.65
plt.subplot(2, 1, 1)
plt.plot(t, similarity(sim.data[in_p], vocab))
plt.plot(t, sim.data[reset_p], c="k", linestyle="--")
plt.ylabel("Input")
plt.ylim(top=1.1)
plt.subplot(2, 1, 2)
plt.plot(t, similarity(sim.data[out_p], vocab))
plt.plot(t[more_a], np.ones(t.shape)[more_a] * 0.9, c="tab:blue", lw=2)
plt.plot(t[more_b], np.ones(t.shape)[more_b] * 0.9, c="tab:orange", lw=2)
plt.ylabel("Output")
assert_sp_close(t, sim.data[out_p], vocab["A"], skip=0.15, duration=0.05)
assert_sp_close(t, sim.data[out_p], vocab["B"], skip=0.65, duration=0.05)
def test_am_default_output(Simulator, plt, seed, rng):
d = 64
vocab = Vocabulary(d, pointer_gen=rng)
vocab.populate("A; B; C; D")
def input_func(t):
return "0.2 * A" if t < 0.25 else "A"
with spa.Network("model", seed=seed) as m:
m.am = ThresholdingAssocMem(
threshold=0.5,
input_vocab=vocab,
mapping=vocab.keys(),
function=filtered_step_fn,
)
m.am.add_default_output("D", 0.5)
m.stimulus = spa.Transcode(input_func, output_vocab=vocab)
m.stimulus >> m.am
in_p = nengo.Probe(m.am.input)
out_p = nengo.Probe(m.am.output, synapse=0.03)
with Simulator(m) as sim:
sim.run(0.5)
t = sim.trange()
below_th = (t > 0.15) & (t < 0.25)
above_th = t > 0.4
plt.subplot(2, 1, 1)
plt.plot(t, similarity(sim.data[in_p], vocab))
plt.ylabel("Input")
plt.subplot(2, 1, 2)
plt.plot(t, similarity(sim.data[out_p], vocab))
plt.plot(t[below_th], np.ones(t.shape)[below_th] * 0.9, c="c", lw=2)
plt.plot(t[above_th], np.ones(t.shape)[above_th] * 0.9, c="b", lw=2)
plt.plot(t[above_th], np.ones(t.shape)[above_th] * 0.1, c="c", lw=2)
plt.ylabel("Output")
assert np.all(similarity(sim.data[out_p][below_th], [vocab["D"].v]) > 0.9)
assert np.all(similarity(sim.data[out_p][above_th], [vocab["D"].v]) < 0.15)
assert np.all(similarity(sim.data[out_p][above_th], [vocab["A"].v]) > 0.9)
def test_am_spa_keys_as_expressions(Simulator, plt, seed, rng):
"""Provide semantic pointer expressions as input and output keys."""
d = 64
vocab_in = Vocabulary(d, pointer_gen=rng)
vocab_out = Vocabulary(d, pointer_gen=rng)
vocab_in.populate("A; B")
vocab_out.populate("C; D")
in_keys = ["A", "A*B"]
out_keys = ["C*D", "C+D"]
mapping = dict(zip(in_keys, out_keys))
with spa.Network(seed=seed) as m:
m.am = ThresholdingAssocMem(threshold=0.3,
input_vocab=vocab_in,
output_vocab=vocab_out,
mapping=mapping)
m.inp = spa.Transcode(lambda t: "A" if t < 0.1 else "A*B",
output_vocab=vocab_in)
m.inp >> m.am
in_p = nengo.Probe(m.am.input)
out_p = nengo.Probe(m.am.output, synapse=0.03)
with nengo.Simulator(m) as sim:
sim.run(0.2)
# Specify t ranges
t = sim.trange()
t_item1 = (t > 0.075) & (t < 0.1)
t_item2 = (t > 0.175) & (t < 0.2)
# Modify vocabularies (for plotting purposes)
vocab_in.add("AxB", vocab_in.parse(in_keys[1]).v)
vocab_out.add("CxD", vocab_out.parse(out_keys[0]).v)
plt.subplot(2, 1, 1)
plt.plot(t, similarity(sim.data[in_p], vocab_in))
plt.ylabel("Input: " + ", ".join(in_keys))
plt.legend(vocab_in.keys(), loc="best")
plt.ylim(top=1.1)
plt.subplot(2, 1, 2)
for t_item, c, k in zip([t_item1, t_item2], ["b", "g"], out_keys):
plt.plot(
t,
similarity(sim.data[out_p], [vocab_out.parse(k).v],
normalize=True),
label=k,
c=c,
)
plt.plot(t[t_item], np.ones(t.shape)[t_item] * 0.9, c=c, lw=2)
plt.ylabel("Output: " + ", ".join(out_keys))
plt.legend(loc="best")
assert (np.mean(
similarity(sim.data[out_p][t_item1],
vocab_out.parse(out_keys[0]).v,
normalize=True)) > 0.9)
assert (np.mean(
similarity(sim.data[out_p][t_item2],
vocab_out.parse(out_keys[1]).v,
normalize=True)) > 0.9)