def setup_optimizers():
global x, y, z
model = init_model(ode_kwargs)
return model
grad_fn = jax.grad(lambda *args: loss_fn(forward, *args))
lr_seq = exponential_decay(step_size=1e-2,
decay_steps=1,
decay_rate=0.999,
lowest=1e-2 / 10)
x, y, z = optimizers.adamax(step_size=lr_seq)
def run():
"""
Run the experiment.
"""
ds_train, ds_test, meta = init_physionet_data(rng, parse_args)
num_batches = meta["num_batches"]
num_test_batches = meta["num_test_batches"]
model = init_model(ode_kwargs)
forward = lambda *args: model["forward"](*args)[1:]
grad_fn = jax.grad(lambda *args: loss_fn(forward, *args))
lr_schedule = exponential_decay(step_size=parse_args.lr,
decay_steps=1,
decay_rate=0.999,
lowest=parse_args.lr / 10)
opt_init, opt_update, get_params = optimizers.adamax(step_size=lr_schedule)
opt_state = opt_init(model["params"])
def get_kl_coef(epoch_):
"""
Tuning schedule for KL coefficient. (annealing)
"""
return max(0., 1 - 0.99**(epoch_ - 10))
@jax.jit
def update(_itr, _opt_state, _batch, kl_coef):
"""
Update the params based on grad for current batch.
"""
return opt_update(_itr, grad_fn(get_params(_opt_state), _batch,
kl_coef), _opt_state)
@jax.jit
def sep_losses(_opt_state, _batch, kl_coef):
"""
Convenience function for calculating losses separately.
"""
params = get_params(_opt_state)
preds, rec_r, gen_r, z0_params, nfe = forward(params,
batch["observed_data"],
batch["observed_tp"],
batch["tp_to_predict"],
batch["observed_mask"])
likelihood_ = _likelihood(preds, batch["observed_data"],
batch["observed_mask"])
mse_ = _mse(preds, batch["observed_data"], batch["observed_mask"])
kl_ = _kl_div(z0_params)
return -logsumexp(likelihood_ - kl_coef * kl_,
axis=0), likelihood_, kl_, mse_, rec_r, gen_r
def evaluate_loss(opt_state, ds_test, kl_coef):
"""
Convenience function for evaluating loss over train set in smaller batches.
"""
loss, likelihood, kl, mse, rec_r, gen_r, rec_nfe, gen_nfe = [], [], [], [], [], [], [], []
for test_batch_num in range(num_test_batches):
test_batch = next(ds_test)
batch_loss, batch_likelihood, batch_kl, batch_mse, batch_rec_r, batch_gen_r = \
sep_losses(opt_state, test_batch, kl_coef)
if count_nfe:
nfes = model["nfe"](get_params(opt_state),
test_batch["observed_data"],
test_batch["observed_tp"],
test_batch["tp_to_predict"],
test_batch["observed_mask"])
rec_nfe.append(nfes["rec"])
gen_nfe.append(nfes["gen"])
else:
rec_nfe.append(0)
gen_nfe.append(0)
loss.append(batch_loss)
likelihood.append(batch_likelihood)
kl.append(batch_kl)
mse.append(batch_mse)
rec_r.append(batch_rec_r)
gen_r.append(batch_gen_r)
loss = jnp.array(loss)
likelihood = jnp.array(likelihood)
kl = jnp.array(kl)
mse = jnp.array(mse)
rec_r = jnp.array(rec_r)
gen_r = jnp.array(gen_r)
rec_nfe = jnp.array(rec_nfe)
gen_nfe = jnp.array(gen_nfe)
return jnp.mean(loss), jnp.mean(likelihood), jnp.mean(kl), jnp.mean(mse), jnp.mean(rec_r), jnp.mean(gen_r), \
jnp.mean(rec_nfe), jnp.mean(gen_nfe)
itr = 0
info = collections.defaultdict(dict)
for epoch in range(parse_args.nepochs):
for i in range(num_batches):
batch = next(ds_train)
itr += 1
opt_state = update(itr, opt_state, batch, get_kl_coef(epoch))
if itr % parse_args.test_freq == 0:
loss_, likelihood_, kl_, mse_, rec_r_, gen_r_, rec_nfe_, gen_nfe_ = \
evaluate_loss(opt_state, ds_test, get_kl_coef(epoch))
print_str = 'Iter {:04d} | Loss {:.6f} | ' \
'Likelihood {:.6f} | KL {:.6f} | MSE {:.6f} | Enc. r {:.6f} | Dec. r {:.6f} | ' \
'Enc. NFE {:.6f} | Dec. NFE {:.6f}'.\
format(itr, loss_, likelihood_, kl_, mse_, rec_r_, gen_r_, rec_nfe_, gen_nfe_)
print(print_str)
outfile = open(
"%s/reg_%s_lam_%.12e_info.txt" % (dirname, reg, lam), "a")
outfile.write(print_str + "\n")
outfile.close()
info[itr]["loss"] = loss_
info[itr]["likelihood"] = likelihood_
info[itr]["kl"] = kl_
info[itr]["mse"] = mse_
info[itr]["rec_r"] = rec_r_
info[itr]["gen_r"] = gen_r_
info[itr]["rec_nfe"] = rec_nfe_
info[itr]["gen_nfe"] = gen_nfe_
if itr % parse_args.save_freq == 0:
param_filename = "%s/reg_%s_lam_%.12e_%d_fargs.pickle" % (
dirname, reg, lam, itr)
fargs = get_params(opt_state)
outfile = open(param_filename, "wb")
pickle.dump(fargs, outfile)
outfile.close()
outfile = open(
"%s/reg_%s_lam_%.12e_iter.txt" % (dirname, reg, lam), "a")
outfile.write("Iter: {:04d}\n".format(itr))
outfile.close()
meta = {"info": info, "args": parse_args}
outfile = open("%s/reg_%s_lam_%.12e_meta.pickle" % (dirname, reg, lam),
"wb")
pickle.dump(meta, outfile)
outfile.close()