def test_cyclical_rate_constant(self):
rate_begin, end_of_period = sgmcmc.cyclical_rate(1, 1)
self.assertAlmostEqual(rate_begin,
1.0,
delta=1.0e-6,
msg='Rate for period_length=1 is not 1.0')
self.assertEqual(bool(end_of_period),
True,
msg='Period length of one but not an end-step.')
def on_train_batch_end(self, batch, logs=None):
self.batch_count += 1
if (self.epoch_count+1) < self.sampling_start_epoch:
return
elif (self.epoch_count+1) == self.sampling_start_epoch and batch == 0:
print('# Starting sampling phase')
timestep_factor, is_cycle_end = sgmcmc.cyclical_rate(
self.cycle_period_length, self.batch_count,
schedule=self.schedule, min_value=self.min_value)
if isinstance(self.model.optimizer, sgmcmc.SGMCMCOptimizer):
tf.keras.backend.set_value(self.model.optimizer.timestep_factor,
timestep_factor)
if is_cycle_end:
print('# Taking ensemble member sample')
self.ensemble.append_maybe(self.model.get_weights)
def test_cyclical_rate(self, period_length, schedule, min_value):
rate_begin, end_of_period = sgmcmc.cyclical_rate(period_length,
1,
schedule=schedule,
min_value=min_value)
self.assertAlmostEqual(
rate_begin,
1.0,
delta=1.0e-6,
msg='Cyclical learning rate at beginning of period '
'not equals to one.')
self.assertEqual(bool(end_of_period),
False,
msg='Beginning marked as end.')
for pi in range(2, period_length):
rate_prev, end_of_period = sgmcmc.cyclical_rate(
period_length, pi - 1, schedule=schedule, min_value=min_value)
rate_cur, _ = sgmcmc.cyclical_rate(period_length,
pi,
schedule=schedule,
min_value=min_value)
self.assertLess(
rate_cur,
rate_prev + 1.0e-6,
msg='Cyclical rate increasing from %.5f to %.5f in '
'period %d to %d' % (rate_prev, rate_cur, pi - 1, pi))
self.assertFalse(
bool(end_of_period),
msg='End of period in the middle of period at index %d '
'with rate %.5f' % (pi - 1, rate_prev))
self.assertGreaterEqual(rate_cur,
min_value,
msg='Minimum value of %.5f not obeyed by '
'rate %.5f' % (min_value, rate_cur))
_, end_of_period = sgmcmc.cyclical_rate(period_length,
period_length,
schedule=schedule,
min_value=min_value)
self.assertTrue(bool(end_of_period), msg='End of period not detected')
with self.assertRaises(ValueError):
sgmcmc.cyclical_rate(period_length, 0)