def test_esn_echo_state_property_norm2():
use_norm2 = True
units = 3
cell = ESNCell(
units=units, use_norm2=use_norm2, recurrent_initializer="ones", connectivity=1.0
)
cell.build((3, 3))
recurrent_weights = tf.constant(cell.get_weights()[0])
max_eig = tf.reduce_max(tf.abs(tf.linalg.eig(recurrent_weights)[0]))
assert max_eig < 1, "max(eig(W)) < 1"
def test_esn_connectivity():
units = 1000
connectivity = 0.5
cell = ESNCell(
units=units,
connectivity=connectivity,
use_norm2=True,
recurrent_initializer="ones",
)
cell.build((3, 3))
recurrent_weights = tf.constant(cell.get_weights()[0])
num_non_zero = tf.math.count_nonzero(recurrent_weights)
actual_connectivity = tf.divide(num_non_zero, units**2)
np.testing.assert_allclose(np.asarray([actual_connectivity]),
np.asanyarray([connectivity]), 1e-2)