def loss_fun(params,
rng,
data,
batch_size=None,
n=None,
loss_type="nlp",
reduce="sum"):
"""
:param batch_size: How large a batch to subselect from the provided data
:param n: The total size of the dataset (to multiply batch estimate by)
"""
assert loss_type in ("nlp", "mse")
inputs, targets = data
n = inputs.shape[0] if n is None else n
if batch_size is not None:
rng, rng_batch = random.split(rng)
i = random.permutation(rng_batch, n)[:batch_size]
inputs, targets = inputs[i], targets[i]
preds = apply_fun(params, rng, inputs).squeeze()
mean_loss = (
-norm.logpdf(targets.squeeze(), preds, params["noise"]).mean()
if loss_type == "nlp" else np.power(targets.squeeze() -
preds, 2).mean())
if reduce == "sum":
loss = n * mean_loss
elif reduce == "mean":
loss = mean_loss
return loss
def generate_nested_circles(key,
n_samples,
inner_radius=2,
outer_radius=4,
noise=0.15):
k1, k2, k3, k4 = random.split(key, 4)
# Generate the circles
inner_t = random.uniform(k1, shape=(n_samples // 2, )) * 2 * jnp.pi
inner_circle = inner_radius * jnp.vstack(
[jnp.cos(inner_t), jnp.sin(inner_t)])
outer_t = random.uniform(k2, shape=(n_samples // 2, )) * 2 * jnp.pi
outer_circle = outer_radius * jnp.vstack(
[jnp.cos(outer_t), jnp.sin(outer_t)])
data = jnp.vstack([inner_circle.T, outer_circle.T])
# Keep track of the labels
y = jnp.hstack([jnp.zeros(n_samples // 2), jnp.ones(n_samples // 2)])
# Shuffle the data
idx = jnp.arange(n_samples)
idx = random.permutation(k3, idx)
data = data[idx]
y = y[idx]
data += random.normal(k4, data.shape) * noise
return data, y
def gibbs_fn(rng_key, gibbs_sites, hmc_sites, pe):
# get support_sizes of gibbs_sites
support_sizes_flat, _ = ravel_pytree({k: support_sizes[k] for k in gibbs_sites})
num_discretes = support_sizes_flat.shape[0]
rng_key, rng_permute = random.split(rng_key)
idxs = random.permutation(rng_key, jnp.arange(num_discretes))
def body_fn(i, val):
idx = idxs[i]
support_size = support_sizes_flat[idx]
rng_key, z, pe = val
rng_key, z_new, pe_new, log_accept_ratio = proposal_fn(
rng_key, z, pe, potential_fn=partial(potential_fn, z_hmc=hmc_sites),
idx=idx, support_size=support_size)
rng_key, rng_accept = random.split(rng_key)
# u ~ Uniform(0, 1), u < accept_ratio => -log(u) > -log_accept_ratio
# and -log(u) ~ exponential(1)
z, pe = cond(random.exponential(rng_accept) > -log_accept_ratio,
(z_new, pe_new), identity,
(z, pe), identity)
return rng_key, z, pe
init_val = (rng_key, gibbs_sites, pe)
_, gibbs_sites, pe = fori_loop(0, num_discretes, body_fn, init_val)
return gibbs_sites, pe
def test_permutation_invariance(self):
num_nodes = 4
num_features = 2
rng = random.PRNGKey(0)
# Generate random graph.
adjacency = random.randint(rng, (num_nodes, num_nodes), 0, 2)
node_feats = random.normal(rng, (num_nodes, num_features))
sources, targets = jnp.where(adjacency)
# Get permuted graph.
perm = random.permutation(rng, jnp.arange(num_nodes))
node_feats_perm = node_feats[perm]
adjacency_perm = adjacency[perm]
for j in range(len(adjacency)):
adjacency_perm = jax.ops.index_update(
adjacency_perm, j, adjacency_perm[j][perm])
sources_perm, targets_perm = jnp.where(adjacency_perm)
# Create GNN.
_, initial_params = GNN.init(
rng, node_x=node_feats, edge_x=None, sources=sources, targets=targets)
model = nn.Model(GNN, initial_params)
# Feedforward both original and permuted graph.
logits = model(node_feats, None, sources, targets)
logits_perm = model(node_feats_perm, None, sources_perm, targets_perm)
self.assertAllClose(logits[perm], logits_perm, check_dtypes=False)
def loss(params, key):
keys = random.split(key, 5)
indices = random.permutation(keys[0],
jnp.arange(X.shape[0]))[:batch_size]
X_batch = X[indices, :]
wind_velocity = random.uniform(keys[1],
shape=(3, ),
minval=jnp.asarray([-200., -200., 0.]),
maxval=jnp.asarray([200., 200., 0.
])) / 1000.
bottom = random.uniform(keys[2], minval=50., maxval=500.)
width = random.uniform(keys[3], minval=40., maxval=300.)
l = random.uniform(keys[4], minval=1., maxval=30.)
sigma = 1.
K = kernel(X_batch,
X_batch,
bottom,
width,
l,
sigma,
wind_velocity=wind_velocity)
neural_kernel.set_params(params)
neural_K = neural_kernel(X_batch,
X_batch,
bottom,
width,
l,
sigma,
wind_velocity=wind_velocity)
return jnp.mean((K - neural_K)**2) / width**2
def _make_minibatches(self, observations, batch_size, rng_key):
'''
Creates minibatches consists of the random permutations of the
given observation sequences
Parameters
----------
observations : array(N, seq_len)
Dataset
batch_size : int
The number of observation sequences that will be included in
each minibatch
rng_key : array
Random key of shape (2,) and dtype uint32
Returns
-------
* array(num_batches, batch_size, max_len)
Minibatches
'''
num_train = len(observations)
perm = permutation(rng_key, num_train)
def create_mini_batch(batch_idx):
return observations[batch_idx]
num_batches = num_train // batch_size
batch_indices = perm.reshape((num_batches, -1))
minibatches = vmap(create_mini_batch)(batch_indices)
return minibatches
def fit(self, X):
opt_init, opt_update, get_params = optimizers.adam(step_size=1e-3)
opt_state = opt_init((self.encoder_params, self.decoder_params))
def loss(params, inputs):
encoder_params, decoder_params = params
enc = self.encoder_apply(encoder_params, X)
dec = self.decoder_apply(decoder_params, X)
return np.square(inputs - dec).sum() + 1e-3 * np.abs(params).sum()
@jit
def step(i, opt_state, inputs):
params = get_params(opt_state)
gradient = grad(loss)(params, inputs)
return opt_update(i, gradient, opt_state)
print('Training autoencoder...')
batch_size, itercount = 32, itertools.count()
key = random.PRNGKey(0)
for epoch in range(5):
temp_key, key = random.split(key)
X = random.permutation(temp_key, X)
for batch_index in range(0, X.shape[0], batch_size):
opt_state = step(next(itercount), opt_state,
X[batch_index:batch_index + batch_size])
self.encoder_params, self.decoder_params = get_params(opt_state)
def loss(rng: jnp.ndarray, bij_params: Sequence[jnp.ndarray],
bij_fns: Sequence[Callable], deq_params: Sequence[jnp.ndarray],
deq_fn: Callable, xon: jnp.ndarray) -> float:
"""Loss function composed of the evidence lower bound and score matching
loss.
Args:
rng: Pseudo-random number generator seed.
bij_params: List of arrays parameterizing the RealNVP bijectors.
bij_fns: List of functions that compute the shift and scale of the RealNVP
affine transformation.
deq_params: Parameters of the mean and scale functions used in
the log-normal dequantizer.
deq_fn: Function that computes the mean and scale of the dequantization
distribution.
xon: Observations on O(n).
Returns:
nelbo: The negative evidence lower bound.
"""
rng, rng_loss, rng_idx = random.split(rng, 3)
idx = random.permutation(rng_idx, len(xon))[:100]
xobs = xon[idx]
if args.elbo_loss:
nelbo = negative_elbo(rng_loss, bij_params, bij_fns, deq_params,
deq_fn, xobs)
nelbo = nelbo.mean()
return nelbo
else:
log_is = importance_log_density(rng_loss, bij_params, bij_fns,
deq_params, deq_fn,
args.num_importance, xobs)
log_target = log_density(xobs)
return jnp.mean(log_target - log_is)
def train_epoch(optimizer, train_ds, batch_size, epoch, rng):
"""Train for a single epoch."""
train_ds_size = len(train_ds['image'])
steps_per_epoch = train_ds_size // batch_size
perms = random.permutation(rng, len(train_ds['image']))
perms = perms[:steps_per_epoch * batch_size] # skip incomplete batch
perms = perms.reshape((steps_per_epoch, batch_size))
batch_metrics = []
for perm in perms:
batch = {k: v[perm] for k, v in train_ds.items()}
optimizer, metrics = train_step(optimizer, batch)
batch_metrics.append(metrics)
# compute mean of metrics across each batch in epoch.
batch_metrics_np = jax.device_get(batch_metrics)
epoch_metrics_np = {
k: onp.mean([metrics[k] for metrics in batch_metrics_np])
for k in batch_metrics_np[0]
}
logging.info('train epoch: %d, loss: %.4f, accuracy: %.2f', epoch,
epoch_metrics_np['loss'], epoch_metrics_np['accuracy'] * 100)
return optimizer, epoch_metrics_np
def data_stream(rng, batch_size, X_train, y_train):
num_batches, leftover = divmod(X_train.shape[0], batch_size)
while True:
temp, rng = random.split(rng)
perm = random.permutation(temp, X_train.shape[0])
for i in range(num_batches):
batch_idx = perm[i * batch_size:(i + 1) * batch_size]
yield X_train[batch_idx], y_train[batch_idx]
def data_stream(rng, batch_size, X, y):
num_complete_batches, leftover = divmod(X.shape[0], batch_size)
num_batches = num_complete_batches + bool(leftover)
while True:
temp, rng = random.split(rng)
perm = random.permutation(temp, X.shape[0])
for i in range(num_batches):
batch_idx = perm[i * batch_size:(i + 1) * batch_size]
yield X[batch_idx], y[batch_idx]
def _make_iaf_args(input_dim, hidden_dims):
_, rng_perm = random.split(random.PRNGKey(0))
perm = random.permutation(rng_perm, np.arange(input_dim))
# we use Elu nonlinearity because the default one, Relu, masks out negative hidden values,
# which in turn create some zero entries in the lower triangular part of Jacobian.
arn_init, arn = AutoregressiveNN(input_dim, hidden_dims, param_dims=[1, 1],
permutation=perm, nonlinearity=stax.Elu)
_, init_params = arn_init(random.PRNGKey(0), (input_dim,))
return partial(arn, init_params),
def data_stream(key, X, y, batch_size):
n_data = len(X)
while True:
perm_key, key = split(key)
perm = permutation(perm_key, n_data)
num_batches, mod = divmod(n_data, batch_size)
num_batches += 1 if mod else 0
for i in range(num_batches):
batch_idx = perm[i * batch_size:min((i + 1) * batch_size, n_data)]
yield X[batch_idx], y[batch_idx]
def __iter__(self) -> Iterator[Batch]:
starts = np.arange(0, len(self.inputs), self.batch_size)
self.key, subkey = random.split(self.key)
starts = random.permutation(subkey, starts)
for start in starts:
end = start + self.batch_size
batch_inputs = self.inputs[start:end]
batch_targets = self.targets[start:end]
yield Batch(batch_inputs, batch_targets)
def data_stream(self, train_images, train_labels, num_train, num_batches,
batch_size):
"""Returns batches of data for training"""
key = random.PRNGKey(0)
while True:
key, subkey = random.split(key)
perm = random.permutation(subkey, num_train)
for i in range(num_batches):
batch_idx = perm[i * batch_size:(i + 1) * batch_size]
yield train_images[batch_idx], train_labels[batch_idx]
def gibbs_fn(rng_key, gibbs_sites, hmc_sites):
# convert to unconstrained values
z_hmc = {
k: biject_to(prototype_trace[k]["fn"].support).inv(v)
for k, v in hmc_sites.items()
if k in prototype_trace and prototype_trace[k]["type"] == "sample"
}
use_enum = len(set(support_sizes) - set(gibbs_sites)) > 0
wrapped_model = _wrap_model(model)
if use_enum:
from numpyro.contrib.funsor import config_enumerate, enum
wrapped_model = enum(config_enumerate(wrapped_model),
-max_plate_nesting - 1)
def potential_fn(z_discrete):
model_kwargs_ = model_kwargs.copy()
model_kwargs_["_gibbs_sites"] = z_discrete
return potential_energy(wrapped_model,
model_args,
model_kwargs_,
z_hmc,
enum=use_enum)
# get support_sizes of gibbs_sites
support_sizes_flat, _ = ravel_pytree(
{k: support_sizes[k]
for k in gibbs_sites})
num_discretes = support_sizes_flat.shape[0]
rng_key, rng_permute = random.split(rng_key)
idxs = random.permutation(rng_key, jnp.arange(num_discretes))
def body_fn(i, val):
idx = idxs[i]
support_size = support_sizes_flat[idx]
rng_key, z, pe = val
rng_key, z_new, pe_new, log_accept_ratio = proposal_fn(
rng_key,
z,
pe,
potential_fn=potential_fn,
idx=idx,
support_size=support_size)
rng_key, rng_accept = random.split(rng_key)
# u ~ Uniform(0, 1), u < accept_ratio => -log(u) > -log_accept_ratio
# and -log(u) ~ exponential(1)
z, pe = cond(
random.exponential(rng_accept) > -log_accept_ratio,
(z_new, pe_new), identity, (z, pe), identity)
return rng_key, z, pe
init_val = (rng_key, gibbs_sites, potential_fn(gibbs_sites))
_, gibbs_sites, _ = fori_loop(0, num_discretes, body_fn, init_val)
return gibbs_sites
def train_one_epoch(params, X_train, y_train, epoch, r):
num_samples = X_train.shape[0]
random_sample_idx = random.permutation(random.PRNGKey(epoch), jnp.arange(num_samples))
for idx in tqdm(range(0, num_samples, BATCH_SIZE)):
mini_batch_idx = random_sample_idx[idx:idx + BATCH_SIZE]
mini_batch_x = X_train[mini_batch_idx]
mini_batch_y = y_train[mini_batch_idx]
params_grad = grad(mlp_loss, argnums=0)(params, mini_batch_x, mini_batch_y)
params, r = apply_grads(params, params_grad, r, LEARNING_RATE)
loss = mlp_loss(params, mini_batch_x, mini_batch_y)
return loss, params, r
def sample_observations(key, f, n_obs, xmin, xmax, x_noise=0.1, y_noise=3.0):
key_x, key_y, key_shuffle = split(key, 3)
x_noise = normal(key_x, (n_obs,)) * x_noise
y_noise = normal(key_y, (n_obs,)) * y_noise
x = jnp.linspace(xmin, xmax, n_obs) + x_noise
y = f(x) + y_noise
X = np.c_[x, y]
shuffled_ixs = permutation(key_shuffle, jnp.arange(n_obs))
x, y = jnp.array(X[shuffled_ixs, :].T)
return x, y
def init_fun(rng, input_dim, **kwargs):
perm = random.permutation(rng, np.arange(input_dim))
inv_perm = np.argsort(perm)
def direct_fun(params, inputs, **kwargs):
return inputs[:, perm], np.zeros(inputs.shape[:1])
def inverse_fun(params, inputs, **kwargs):
return inputs[:, inv_perm], np.zeros(inputs.shape[:1])
return (), direct_fun, inverse_fun
def testPermutationInteger(self):
key = random.PRNGKey(0)
x = 100
rand = lambda key: random.permutation(key, x)
crand = api.jit(rand)
perm1 = rand(key)
perm2 = crand(key)
self.assertAllClose(perm1, perm2)
self.assertEqual(perm1.dtype, perm2.dtype)
self.assertFalse(np.all(perm1 == np.arange(100))) # seems unlikely!
self.assertAllClose(np.sort(perm1), np.arange(100), check_dtypes=False)
def gibbs_fn(rng_key, gibbs_sites, hmc_sites):
z_hmc = hmc_sites
use_enum = len(set(support_sizes) - set(gibbs_sites)) > 0
if use_enum:
from numpyro.contrib.funsor import config_enumerate, enum
wrapped_model_ = enum(config_enumerate(wrapped_model),
-max_plate_nesting - 1)
else:
wrapped_model_ = wrapped_model
def potential_fn(z_discrete):
model_kwargs_ = model_kwargs.copy()
model_kwargs_["_gibbs_sites"] = z_discrete
return potential_energy(wrapped_model_,
model_args,
model_kwargs_,
z_hmc,
enum=use_enum)
# get support_sizes of gibbs_sites
support_sizes_flat, _ = ravel_pytree(
{k: support_sizes[k]
for k in gibbs_sites})
num_discretes = support_sizes_flat.shape[0]
rng_key, rng_permute = random.split(rng_key)
idxs = random.permutation(rng_key, jnp.arange(num_discretes))
def body_fn(i, val):
idx = idxs[i]
support_size = support_sizes_flat[idx]
rng_key, z, pe = val
rng_key, z_new, pe_new, log_accept_ratio = proposal_fn(
rng_key,
z,
pe,
potential_fn=potential_fn,
idx=idx,
support_size=support_size)
rng_key, rng_accept = random.split(rng_key)
# u ~ Uniform(0, 1), u < accept_ratio => -log(u) > -log_accept_ratio
# and -log(u) ~ exponential(1)
z, pe = cond(
random.exponential(rng_accept) > -log_accept_ratio,
(z_new, pe_new), identity, (z, pe), identity)
return rng_key, z, pe
init_val = (rng_key, gibbs_sites, potential_fn(gibbs_sites))
_, gibbs_sites, _ = fori_loop(0, num_discretes, body_fn, init_val)
return gibbs_sites
def testPermutationArray(self, dtype, shape):
key = random.PRNGKey(0)
x = jnp.arange(np.prod(shape)).reshape(shape).astype(dtype)
rand = lambda key: random.permutation(key, x)
crand = api.jit(rand)
perm1 = rand(key)
perm2 = crand(key)
self.assertAllClose(perm1, perm2)
self.assertFalse(np.all(perm1 == x)) # seems unlikely!
self.assertAllClose(np.sort(perm1.ravel()), x.ravel(), check_dtypes=False)
self.assertArraysAllClose(
x, jnp.arange(np.prod(shape)).reshape(shape).astype(dtype))
def get_batch(sampling, key, X, minibatch_size, iteration):
if sampling == 'batch':
# Calculate epoch from iteration
epoch = iteration // (X.shape[0] // minibatch_size)
batch_index = iteration % (X.shape[0] // minibatch_size)
batch_index_start = batch_index * minibatch_size
# Regular batching
if batch_index == 0:
temp_key, key = random.split(key)
X = random.permutation(temp_key, X)
return X[batch_index_start:batch_index_start+minibatch_size], X
elif sampling == 'uniform':
# Uniform subsampling
temp_key, key = random.split(key)
X = random.permutation(temp_key, X)
return X[:minibatch_size], X
elif sampling == 'poisson':
# Poisson subsampling
temp_key, key = random.split(key)
whether = random.uniform(temp_key, (X.shape[0],)) < (minibatch_size / X.shape[0])
return X[whether], X
else:
raise Exception('Invalid sampling method: {}'.format(sampling))
def epoch_step(opt_state, key):
perm = permutation(key, len(observations))
_observatios, _targets = observations[perm], targets[perm]
sample_generator = self._sample_minibatches(
(_observatios, _targets), batch_size)
def train_step(opt_state, i):
opt_state, loss = self.update(next(itercount), opt_state,
next(sample_generator))
return opt_state, loss
opt_state, losses = scan(train_step, opt_state,
jnp.arange(num_batches))
return opt_state, losses.mean()
def load_mnist(key, n_train, n_test, shuffle=True):
(X, y), (X_test, y_test) = mnist.load_data()
n_train = n_train if n_train < len(y) else len(y)
n_test = n_test if n_test < len(y_test) else len(y)
train_key, test_key = split(key)
train_indices = jnp.arange(len(y))
perm = permutation(train_key, train_indices)[:n_train] if shuffle else train_indices[:n_train]
train_ds = {
"X": jnp.float32(X[perm].reshape(n_train, -1)) / 255.,
"y": jnp.array(y[perm])
}
test_indices = jnp.arange(len(y_test))
perm = permutation(test_key, test_indices)[:n_test] if shuffle else test_indices[:n_test]
test_ds = {
"X": jnp.float32(X_test[perm].reshape(n_test, -1)) / 255.,
"y": jnp.array(y_test[perm])
}
return train_ds, test_ds
def testPermutationArray(self, dtype):
key = random.PRNGKey(0)
x = onp.arange(100).astype(dtype)
rand = lambda key: random.permutation(key, x)
crand = api.jit(rand)
perm1 = rand(key)
perm2 = crand(key)
self.assertAllClose(perm1, perm2, check_dtypes=True)
self.assertEqual(perm1.dtype, perm2.dtype)
self.assertFalse(onp.all(perm1 == x)) # seems unlikely!
self.assertAllClose(onp.sort(perm1), x, check_dtypes=False)
self.assertArraysAllClose(x, onp.arange(100).astype(dtype),
check_dtypes=True)
def train_test_split(data, rng=None, n_test=None):
"""
Create a train-test split
"""
rng = PRNGKey(42) if rng is None else rng
n = len(data.x)
rng, rng_perm = split(rng)
i = permutation(rng, n)
n_test = min(16384, int(0.1 * n)) if n_test is None else n_test
if isinstance(n_test, float):
n_test = int(n_test * n)
n_train = n - n_test
i_train, i_test = i[:n_train], i[n_train:]
return (
Data(data.x[i_train], data.y[i_train]),
Data(data.x[i_test], data.y[i_test]),
)
def next_mask(self, prev_sel, size, rng):
# Choose the degrees of the next layer
max_connection = self.dim - 1 if self.triangular_jacobian == False else self.dim
if self.method == "random":
sel = random.randint(rng, shape=(size,), minval=min(jnp.min(sel), max_connection), maxval=dim)
elif "sequential" in self.method:
sel = jnp.arange(size)%max(1, max_connection) + min(1, max_connection)
if self.method == "shuffled_sequential":
sel = random.permutation(rng, sel)
else:
assert 0, "Invalid mask method"
# Create the new mask
mask = (prev_sel[:,None] <= sel).astype(jnp.int32)
return mask, sel
def data_preprocessing():
""" Seperates data (spin configurations) into test and training set and generates labels"""
rng = random.PRNGKey(0)
temperatures = jnp.linspace(1.0, 4.0, 7)
temperatures1 = [1.0, 1.5, 3.0, 3.5, 4.0]
temperatures2 = [2.0, 2.5]
x_train = []
y_train = []
x_test = []
y_test = []
for T in temperatures:
configs = jnp.load('data/spins_T%s.npy' % T)
magnetization_density = jnp.abs(
jnp.array([jnp.sum(config) / config.size for config in configs]))
labels = jnp.where(magnetization_density < 0.5, 0, 1)
if T in temperatures2:
x_test.append(configs)
y_test.append(labels)
else:
indices = random.permutation(rng, labels.size)
y_test.append(labels[indices[:int(0.2 * labels.size)]])
y_train.append(labels[indices[int(0.2 * labels.size):]])
x_test.append(configs[indices[:int(0.2 * labels.size)]])
x_train.append(configs[indices[int(0.2 * labels.size):]])
y_test_new = jnp.array(y_test[0])
x_test_new = jnp.array(x_test[0])
for i in range(len(y_test) - 1):
y_test_new = jnp.concatenate((y_test_new, y_test[i + 1]))
x_test_new = jnp.concatenate((x_test_new, x_test[i + 1]))
L = jnp.array(x_train).shape[2]
x_test = jnp.array(x_test_new).reshape((-1, L, L, 1)).astype(jnp.float64)
y_test = jnp.array(y_test_new).reshape((-1, 1))
x_train = jnp.array(x_train).reshape((-1, L, L, 1)).astype(jnp.float64)
y_train = jnp.array(y_train).reshape((-1, 1))
jnp.save('data/x_test.npy', x_test)
jnp.save('data/y_test.npy', y_test)
jnp.save('data/x_train.npy', x_train)
jnp.save('data/y_train.npy', y_train)
return x_train, y_train, x_test, y_test
def init_fun(rng, input_dim, **kwargs):
perm = random.permutation(rng, np.arange(input_dim))
inv_perm = np.argsort(perm)
@ForwardFunction
def forward_fun(params, inputs, **kwargs):
outputs = inputs[:, perm]
log_det = np.zeros(inputs.shape[0])
return outputs, log_det
@InverseFunction
def inverse_fun(params, inputs, **kwargs):
outputs = inputs[:, inv_perm]
log_det = np.zeros(inputs.shape[0])
return outputs, log_det
return (), forward_fun, inverse_fun
