def test_binary_vis_layer_sample():
# Verifies that BinaryVector.sample returns an expression
# whose value passes check_binary_samples
assert hasattr(np, 'exp')
n = 5
num_samples = 1000
tol = .04
class DummyLayer(object):
"""
A layer that we build for the test that just uses a state
as its downward message.
"""
def downward_state(self, state):
return state
def downward_message(self, state):
return state
vis = BinaryVector(nvis=n)
hid = DummyLayer()
rng = np.random.RandomState([2012,11,1,259])
mean = rng.uniform(1e-6, 1. - 1e-6, (n,))
ofs = rng.randn(n)
vis.set_biases(ofs.astype(config.floatX))
z = inverse_sigmoid_numpy(mean) - ofs
z_var = sharedX(np.zeros((num_samples, n)) + z)
theano_rng = MRG_RandomStreams(2012+11+1)
sample = vis.sample(state_above=z_var, layer_above=hid,
theano_rng=theano_rng)
sample = sample.eval()
check_binary_samples(sample, (num_samples, n), mean, tol)
