def test_ops(self):
x = K.variable(np.random.rand(8, 12))
y = K.variable(np.random.rand(12, 25))
z = K.placeholder((25, 18, 13))
w = K.placeholder((18, 18))
# ====== dot ====== #
t = K.dot(x, y)
self.assertEquals(K.get_shape(t), (8, 25))
self.assertEquals(K.get_shape(t), K.eval(t).shape)
t = K.dot(t, K.dimshuffle(z, (1, 0, 2)))
self.assertEquals(K.get_shape(t), (8, 18, 13))
# ====== transpose ====== #
self.assertEquals(K.get_shape(K.transpose(z)), (13, 18, 25))
self.assertEquals(K.get_shape(K.transpose(t, axes=(2, 0, 1))),
(13, 8, 18))
# ====== eye ====== #
self.assertEquals(K.get_shape(K.eye(5)), K.eval(K.eye(5)).shape)
# ====== diag ====== #
self.assertEquals(K.get_shape(K.diag(w)), (18, ))
# self.assertEquals(K.get_shape(K.diag(x)),
# K.eval(K.diag(y)).shape)
self.assertEquals(K.get_shape(K.square(x)), K.eval(K.square(x)).shape)
self.assertEquals(K.get_shape(K.abs(x)), K.eval(K.abs(x)).shape)
self.assertEquals(K.get_shape(K.sqrt(x)), K.eval(K.sqrt(x)).shape)
self.assertEquals(K.get_shape(K.exp(x)), K.eval(K.exp(x)).shape)
self.assertEquals(K.get_shape(K.log(x)), K.eval(K.log(x)).shape)
self.assertEquals(K.get_shape(K.round(x)), K.eval(K.round(x)).shape)
self.assertEquals(K.get_shape(K.pow(x, 2)), K.eval(K.pow(x, 2)).shape)
self.assertEquals(K.get_shape(K.clip(x, -1, 1)),
K.eval(K.clip(x, -1, 1)).shape)
self.assertEquals(K.get_shape(K.inv(x)), K.eval(K.inv(x)).shape)
def sampling(self, x):
mean, logsigma = self.get_mean_logsigma(x)
epsilon = K.random_normal(shape=K.get_shape(mean),
mean=0.0,
std=1.0,
dtype=mean.dtype)
z = mean + K.exp(logsigma) * epsilon
return z
def test_basic_ops_value(self):
np.random.seed(12082518)
x = K.variable(np.random.randn(8, 8))
y = K.variable(np.random.randn(8, 8))
z = K.variable(np.random.randint(0, 2, size=(8, 8)), dtype=np.bool)
w = K.variable(np.random.randint(0, 2, size=(8, 8)), dtype=np.bool)
self.assertEqual(round(np.sum(K.eval(K.relu(x, alpha=0.12))) * 10000),
276733)
self.assertEqual(round(np.sum(K.eval(K.elu(x, alpha=0.12))) * 10000),
289202)
self.assertEqual(np.sum(K.eval(K.softmax(x))), 8.0)
self.assertEqual(round(np.sum(K.eval(K.softplus(x))) * 10000), 554564)
self.assertEqual(round(np.sum(K.eval(K.softsign(x))) * 100000), 211582)
self.assertEqual(round(np.sum(K.eval(K.sigmoid(x))) * 10000), 330427)
self.assertEqual(round(np.sum(K.eval(K.hard_sigmoid(x))) * 10000),
330836)
self.assertEqual(round(np.sum(K.eval(K.tanh(x))) * 100000), 290165)
self.assertEqual(round(np.sum(K.eval(K.square(x))) * 10000), 744492)
self.assertEqual(round(np.sum(K.eval(K.sqrt(x))) * 10000), 300212)
self.assertEqual(round(np.sum(K.eval(K.abs(x))) * 10000), 559979)
self.assertEqual(np.sum(K.eval(K.sign(x))), 6.0)
self.assertEqual(round(np.sum(K.eval(K.inv(x))) * 1000), 495838)
self.assertEqual(round(np.sum(K.eval(K.exp(x))) * 1000), 122062)
self.assertEqual(round(np.sum(K.eval(K.log(K.abs(x)))) * 10000),
-344491)
self.assertEqual(np.sum(K.eval(K.round(x))), 5.0)
self.assertEqual(round(np.sum(K.eval(K.pow(x, 8))) * 100), 398153)
self.assertEqual(
round(np.sum(K.eval(K.clip(x, -0.12, 0.12))) * 1000000), 620529)
# TODO: pygpu (libgpuarray) still not support diag
# self.assertEqual(round(np.sum(K.eval(K.diag(x))) * 100000), 325289)
self.assertEqual(np.sum(K.eval(K.eye(12, 8))), 8.0)
self.assertEqual(np.sum(K.eval(K.eq(z, w))), 38)
self.assertEqual(np.sum(K.eval(K.neq(z, w))), 26)
self.assertEqual(np.sum(K.eval(K.gt(x, y))), 33)
self.assertEqual(np.sum(K.eval(K.ge(x, y))), 33)
self.assertEqual(np.sum(K.eval(K.lt(x, y))), 31)
self.assertEqual(np.sum(K.eval(K.le(x, y))), 31)
self.assertEqual(round(np.sum(K.eval(K.switch(z, x, y))) * 100000),
139884)
def score(self,
query,
key=None,
scale=1,
window_width=None,
q_proj=None,
target_proj=None):
r"""
Arguments:
query: Query (or target sequence) tensor of shape
`[batch_size, Tq, dim]` or `[num_heads, batch_size, Tq, dim]` in case
of multi-heads attention.
key: Key (or source sequence) tensor of shape
`[batch_size, Tv, dim]` or `[num_heads, batch_size, Tv, dim]` in case
of multi-heads attention.
scale: single `Scalar` or `Tensor` of shape `[dim]` for scaling
the attention scores, suggested `1/sqrt(dim)` in (Vaswani et al. 2017).
window_width : `None`, `Integer` or `Float` ([0, 1]). The total number of
frames for a single window in local attention (i.e. `left + 1 + right`)
Can be given as a fixed number of frames (`int`), or percentage of
the sequence length (`float`). If `None`, use `Tq`
q_proj : `Dense`, instance of dense or fully connected layer
- for `ScoreLocation`, the number of hidden unit is `1`
- for `ScoreGeneral`, the number of hidden unit is `dim`
target_proj : `Dense`, for predictive local attention, applying
a fully connected network on target sequence (i.e. the query) to
predict the position on source sequence (i.e. the key).
The layer must has output dimension equal to 1 and return logit value.
Returns:
Tensor of shape `[num_heads, batch_size, Tq, Tv]`, or
`[num_heads, batch_size, Tq, 1]` if `ScoreLocation`
"""
### Check if multi-head attention is used
num_heads = _get_num_heads(query)
if num_heads > 0:
query = bk.reshape(query, [-1] + [i for i in query.shape[2:]])
if key is not None:
key = bk.reshape(key, [-1] + [i for i in key.shape[2:]])
Tq = query.shape[1]
Tv = Tq if key is None else key.shape[1]
# scale shape is `[]` or `[dim]`
scale = bk.array(scale, dtype=query.dtype)
### Check the window width
if window_width is None:
window_width = Tq
elif window_width < 1:
window_width = window_width * Tv
window_width = int(window_width)
### Locative attention
if AttentionMechanism.ScoreLocation in self:
if PosLocalM in self or PosLocalP in self:
raise NotImplementedError(
"ScoreLocation only support Global attention, but given: %s"
% str(self))
# [batch_size * num_heads, Tq, dim]
scores = bk.reduce_mean(scale) * q_proj(query)
assert scores.shape[-1] == 1, \
" q_proj must have only 1 hidden unit, but given %d" % scores.shape[-1]
### Other score mode need the key tensor
else:
if key is None:
raise ValueError(
"key must be provided for attention type: %s" % str(self))
### Attention position (local or global)
if PosLocalM in self:
key = key[:, -window_width:]
elif PosLocalP in self:
pt = bk.sigmoid(target_proj(bk.reshape(query, ([0], -1))))
assert pt.shape[-1] == 1, \
"target_proj must project the query [., Tq * dim] to [., 1], i.e. " + \
"predicting the attention position on source sequence using " + \
"knowledge from target sequence."
pt = Tv * pt # `[batch_size * num_heads, 1]`
# `[batch_size * num_heads, Tv]`
# Eq (10) (Luong et al. 2015)
gauss_est = bk.exp(
-bk.square(bk.arange(Tv, dtype=pt.dtype) - pt) /
(2 * bk.square(window_width / 2)))
# `[batch_size * num_heads, 1, Tv]`
gauss_est = bk.expand_dims(gauss_est, axis=1)
### Additive or concat method
if AttentionMechanism.ScoreAdditive in self:
# [batch_size * num_heads, Tq, 1, dim]
q = bk.expand_dims(query, axis=2)
# [batch_size * num_heads, 1, Tv, dim]
k = bk.expand_dims(key, axis=1)
# [batch_size * num_heads, Tq, Tv]
scores = bk.reduce_sum(scale * bk.tanh(q + k), axis=-1)
### Dot product or multiplicative scoring
elif AttentionMechanism.ScoreDotProd in self:
# this is a trick to make attention_scale broadcastable when
# scale_tied=False
scores = bk.matmul(scale * query, bk.swapaxes(key, 1, 2))
### cosine scoring
elif AttentionMechanism.ScoreCosine in self:
# [batch_size * num_heads, Tq, 1, dim]
q = bk.expand_dims(query, axis=2)
# [batch_size * num_heads, 1, Tv, dim]
k = bk.expand_dims(key, axis=1)
# [batch_size * num_heads, Tq, Tv, dim]
scores = (q * k) / (bk.norm(q, p=2) * bk.norm(k, p=2))
scores = bk.reduce_sum(scale * scores, axis=-1, keepdims=False)
### general method with only project on the query
elif AttentionMechanism.ScoreGeneral in self:
query = q_proj(query)
assert query.shape[-1] == key.shape[-1], \
" q_proj must have %d hidden units, but given %d units" % \
(key.shape[-1], query.shape[-1])
scores = bk.matmul(scale * query, bk.swapaxes(key, 1, 2))
else:
raise NotImplementedError(
"No support for attention_type='%s'" % str(self))
### applying the local-predictive attention
if PosLocalP in self:
scores = scores * gauss_est
### get back the multi-heads shape
if num_heads > 0:
scores = bk.reshape(scores,
shape=[num_heads, -1] +
[i for i in scores.shape[1:]])
return scores
