def test_svhn(occ_dim=15, drop_prob=0.0):
RESULT_PATH = "IMP_SVHN_VAE/"
#########################################
# Format the result tag more thoroughly #
#########################################
dp_int = int(100.0 * drop_prob)
result_tag = "{}VAE_OD{}_DP{}".format(RESULT_PATH, occ_dim, dp_int)
##########################
# Get some training data #
##########################
tr_file = 'data/svhn_train_gray.pkl'
te_file = 'data/svhn_test_gray.pkl'
ex_file = 'data/svhn_extra_gray.pkl'
data = load_svhn_gray(tr_file, te_file, ex_file=ex_file, ex_count=200000)
Xtr = to_fX( shift_and_scale_into_01(np.vstack([data['Xtr'], data['Xex']])) )
Xva = to_fX( shift_and_scale_into_01(data['Xte']) )
tr_samples = Xtr.shape[0]
va_samples = Xva.shape[0]
batch_size = 250
all_pix_mean = np.mean(np.mean(Xtr, axis=1))
data_mean = to_fX( all_pix_mean * np.ones((Xtr.shape[1],)) )
############################################################
# Setup some parameters for the Iterative Refinement Model #
############################################################
obs_dim = Xtr.shape[1]
z_dim = 100
imp_steps = 15 # we'll check for the best step count (found oracularly)
init_scale = 1.0
x_in_sym = T.matrix('x_in_sym')
x_out_sym = T.matrix('x_out_sym')
x_mask_sym = T.matrix('x_mask_sym')
#################
# p_zi_given_xi #
#################
params = {}
shared_config = [obs_dim, 1000, 1000]
top_config = [shared_config[-1], z_dim]
params['shared_config'] = shared_config
params['mu_config'] = top_config
params['sigma_config'] = top_config
params['activation'] = relu_actfun
params['init_scale'] = init_scale
params['lam_l2a'] = 0.0
params['vis_drop'] = 0.0
params['hid_drop'] = 0.0
params['bias_noise'] = 0.0
params['input_noise'] = 0.0
params['build_theano_funcs'] = False
p_zi_given_xi = InfNet(rng=rng, Xd=x_in_sym, \
params=params, shared_param_dicts=None)
p_zi_given_xi.init_biases(0.2)
###################
# p_xip1_given_zi #
###################
params = {}
shared_config = [z_dim, 1000, 1000]
output_config = [obs_dim, obs_dim]
params['shared_config'] = shared_config
params['output_config'] = output_config
params['activation'] = relu_actfun
params['init_scale'] = init_scale
params['lam_l2a'] = 0.0
params['vis_drop'] = 0.0
params['hid_drop'] = 0.0
params['bias_noise'] = 0.0
params['input_noise'] = 0.0
params['build_theano_funcs'] = False
p_xip1_given_zi = HydraNet(rng=rng, Xd=x_in_sym, \
params=params, shared_param_dicts=None)
p_xip1_given_zi.init_biases(0.2)
###################
# q_zi_given_x_xi #
###################
params = {}
shared_config = [(obs_dim + obs_dim), 1000, 1000]
top_config = [shared_config[-1], z_dim]
params['shared_config'] = shared_config
params['mu_config'] = top_config
params['sigma_config'] = top_config
params['activation'] = relu_actfun
params['init_scale'] = init_scale
params['lam_l2a'] = 0.0
params['vis_drop'] = 0.0
params['hid_drop'] = 0.0
params['bias_noise'] = 0.0
params['input_noise'] = 0.0
params['build_theano_funcs'] = False
q_zi_given_x_xi = InfNet(rng=rng, Xd=x_in_sym, \
params=params, shared_param_dicts=None)
q_zi_given_x_xi.init_biases(0.2)
###########################################################
# Define parameters for the GPSImputer, and initialize it #
###########################################################
print("Building the GPSImputer...")
gpsi_params = {}
gpsi_params['obs_dim'] = obs_dim
gpsi_params['z_dim'] = z_dim
gpsi_params['imp_steps'] = imp_steps
gpsi_params['step_type'] = 'jump'
gpsi_params['x_type'] = 'bernoulli'
gpsi_params['obs_transform'] = 'sigmoid'
gpsi_params['use_osm_mode'] = True
GPSI = GPSImputer(rng=rng,
x_in=x_in_sym, x_out=x_out_sym, x_mask=x_mask_sym, \
p_zi_given_xi=p_zi_given_xi, \
p_xip1_given_zi=p_xip1_given_zi, \
q_zi_given_x_xi=q_zi_given_x_xi, \
params=gpsi_params, \
shared_param_dicts=None)
#########################################################################
# Define parameters for the underlying OneStageModel, and initialize it #
#########################################################################
print("Building the OneStageModel...")
osm_params = {}
osm_params['x_type'] = 'bernoulli'
osm_params['xt_transform'] = 'sigmoid'
OSM = OneStageModel(rng=rng, \
x_in=x_in_sym, \
p_x_given_z=p_xip1_given_zi, \
q_z_given_x=p_zi_given_xi, \
x_dim=obs_dim, z_dim=z_dim, \
params=osm_params)
################################################################
# Apply some updates, to check that they aren't totally broken #
################################################################
log_name = "{}_RESULTS.txt".format(result_tag)
out_file = open(log_name, 'wb')
costs = [0. for i in range(10)]
learn_rate = 0.0002
momentum = 0.5
batch_idx = np.arange(batch_size) + tr_samples
for i in range(200005):
scale = min(1.0, ((i+1) / 5000.0))
if (((i + 1) % 15000) == 0):
learn_rate = learn_rate * 0.92
if (i > 10000):
momentum = 0.90
else:
momentum = 0.50
# get the indices of training samples for this batch update
batch_idx += batch_size
if (np.max(batch_idx) >= tr_samples):
# we finished an "epoch", so we rejumble the training set
Xtr = row_shuffle(Xtr)
batch_idx = np.arange(batch_size)
# set sgd and objective function hyperparams for this update
OSM.set_sgd_params(lr=scale*learn_rate, \
mom_1=scale*momentum, mom_2=0.99)
OSM.set_lam_nll(lam_nll=1.0)
OSM.set_lam_kld(lam_kld_1=1.0, lam_kld_2=0.0)
OSM.set_lam_l2w(1e-4)
# perform a minibatch update and record the cost for this batch
xb = to_fX( Xtr.take(batch_idx, axis=0) )
result = OSM.train_joint(xb, batch_reps)
costs = [(costs[j] + result[j]) for j in range(len(result)-1)]
if ((i % 250) == 0):
costs = [(v / 250.0) for v in costs]
str1 = "-- batch {0:d} --".format(i)
str2 = " joint_cost: {0:.4f}".format(costs[0])
str3 = " nll_cost : {0:.4f}".format(costs[1])
str4 = " kld_cost : {0:.4f}".format(costs[2])
str5 = " reg_cost : {0:.4f}".format(costs[3])
joint_str = "\n".join([str1, str2, str3, str4, str5])
print(joint_str)
out_file.write(joint_str+"\n")
out_file.flush()
costs = [0.0 for v in costs]
if ((i % 1000) == 0):
Xva = row_shuffle(Xva)
# record an estimate of performance on the test set
xi, xo, xm = construct_masked_data(Xva[0:5000], drop_prob=drop_prob, \
occ_dim=occ_dim, data_mean=data_mean)
step_nll, step_kld = GPSI.compute_per_step_cost(xi, xo, xm, sample_count=10)
min_nll = np.min(step_nll)
str1 = " va_nll_bound : {}".format(min_nll)
str2 = " va_nll_min : {}".format(min_nll)
str3 = " va_nll_final : {}".format(step_nll[-1])
joint_str = "\n".join([str1, str2, str3])
print(joint_str)
out_file.write(joint_str+"\n")
out_file.flush()
if ((i % 10000) == 0):
# Get some validation samples for evaluating model performance
xb = to_fX( Xva[0:100] )
xi, xo, xm = construct_masked_data(xb, drop_prob=drop_prob, \
occ_dim=occ_dim, data_mean=data_mean)
xi = np.repeat(xi, 2, axis=0)
xo = np.repeat(xo, 2, axis=0)
xm = np.repeat(xm, 2, axis=0)
# draw some sample imputations from the model
samp_count = xi.shape[0]
_, model_samps = GPSI.sample_imputer(xi, xo, xm, use_guide_policy=False)
seq_len = len(model_samps)
seq_samps = np.zeros((seq_len*samp_count, model_samps[0].shape[1]))
idx = 0
for s1 in range(samp_count):
for s2 in range(seq_len):
seq_samps[idx] = model_samps[s2][s1]
idx += 1
file_name = "{}_samples_ng_b{}.png".format(result_tag, i)
utils.visualize_samples(seq_samps, file_name, num_rows=20)
# get visualizations of policy parameters
file_name = "{}_gen_gen_weights_b{}.png".format(result_tag, i)
W = GPSI.gen_gen_weights.get_value(borrow=False)
utils.visualize_samples(W[:,:obs_dim], file_name, num_rows=20)
file_name = "{}_gen_inf_weights_b{}.png".format(result_tag, i)
W = GPSI.gen_inf_weights.get_value(borrow=False).T
utils.visualize_samples(W[:,:obs_dim], file_name, num_rows=20)
