Exemplo n.º 1
0
    def test_scale_by_fromage(self):
        schedule = lambda c: 1.0 / (c + 1.0)
        fromage = transform.scale_by_fromage(step_size_factor_fn=schedule)
        params = self.init_params
        state = fromage.init(params)
        previous_norm = jnp.inf
        transform_fn = self.variant(fromage.update)

        for _ in range(STEPS):
            # Apply a step of fromage
            updates, state = transform_fn(self.per_step_updates, state, params)
            # Updates should get smaller due to the the learning schedule.
            norm = transform.global_norm(updates)
            self.assertLess(norm, previous_norm)
            previous_norm = norm
Exemplo n.º 2
0
class AliasTest(chex.TestCase):
    def setUp(self):
        super(AliasTest, self).setUp()
        self.init_params = (jnp.array([1., 2.]), jnp.array([3., 4.]))
        self.per_step_updates = (jnp.array([500., 5.]), jnp.array([300., 3.]))

    @chex.all_variants()
    @parameterized.named_parameters(
        ('sgd', alias.sgd(LR, 0.0), optimizers.sgd(LR), 1e-5),
        ('adam', alias.adam(LR, 0.9, 0.999,
                            1e-8), optimizers.adam(LR, 0.9, 0.999), 1e-4),
        ('rmsprop', alias.rmsprop(LR, .9, 0.1), optimizers.rmsprop(
            LR, .9, 0.1), 1e-5),
        ('adagrad', alias.adagrad(
            LR,
            0.,
            0.,
        ), optimizers.adagrad(LR, 0.), 1e-5),
    )
    def test_jax_optimizer_equivalent(self, optax_optimizer, jax_optimizer,
                                      rtol):

        # experimental/optimizers.py
        jax_params = self.init_params
        opt_init, opt_update, get_params = jax_optimizer
        state = opt_init(jax_params)
        for i in range(STEPS):
            state = opt_update(i, self.per_step_updates, state)
            jax_params = get_params(state)

        # optax
        optax_params = self.init_params
        state = optax_optimizer.init(optax_params)

        @self.variant
        def step(updates, state):
            return optax_optimizer.update(updates, state)

        for _ in range(STEPS):
            updates, state = step(self.per_step_updates, state)
            optax_params = update.apply_updates(optax_params, updates)

        # Check equivalence.
        chex.assert_tree_all_close(jax_params, optax_params, rtol=rtol)

    @parameterized.named_parameters(
        ('sgd', alias.sgd(1e-2, 0.0)),
        ('adam', alias.adam(1e-1)),
        ('adamw', alias.adamw(1e-1)),
        ('lamb', alias.adamw(1e-1)),
        ('rmsprop', alias.rmsprop(1e-1)),
        ('fromage', transform.scale_by_fromage(-1e-2)),
        ('adabelief', alias.adabelief(1e-1)),
    )
    def test_parabel(self, opt):
        initial_params = jnp.array([-1.0, 10.0, 1.0])
        final_params = jnp.array([1.0, -1.0, 1.0])

        @jax.grad
        def get_updates(params):
            return jnp.sum((params - final_params)**2)

        @jax.jit
        def step(params, state):
            updates, state = opt.update(get_updates(params), state, params)
            params = update.apply_updates(params, updates)
            return params, state

        params = initial_params
        state = opt.init(params)
        for _ in range(1000):
            params, state = step(params, state)

        chex.assert_tree_all_close(params, final_params, rtol=1e-2, atol=1e-2)

    @parameterized.named_parameters(
        ('sgd', alias.sgd(2e-3, 0.2)),
        ('adam', alias.adam(1e-1)),
        ('adamw', alias.adamw(1e-1)),
        ('lamb', alias.adamw(1e-1)),
        ('rmsprop', alias.rmsprop(5e-3)),
        ('fromage', transform.scale_by_fromage(-5e-3)),
        ('adabelief', alias.adabelief(1e-1)),
    )
    def test_rosenbrock(self, opt):
        a = 1.0
        b = 100.0
        initial_params = jnp.array([0.0, 0.0])
        final_params = jnp.array([a, a**2])

        @jax.grad
        def get_updates(params):
            return (a - params[0])**2 + b * (params[1] - params[0]**2)**2

        @jax.jit
        def step(params, state):
            updates, state = opt.update(get_updates(params), state, params)
            params = update.apply_updates(params, updates)
            return params, state

        params = initial_params
        state = opt.init(params)
        for _ in range(10000):
            params, state = step(params, state)

        chex.assert_tree_all_close(params, final_params, rtol=3e-2, atol=3e-2)