def _lstm(X, settings, parameters, memory):
n_filters = settings['n_filters'] * 4
X_weight, h_weight, bias = parameters
previous_h, previous_c = memory
if previous_h is 0:
array = _lstm_convolution(X, n_filters, X_weight)
array = layers.broadcast_plus(array, bias)
else:
array = _lstm_convolution(X, n_filters, X_weight) + _lstm_convolution(previous_h, n_filters, h_weight)
array = layers.broadcast_plus(array, bias)
group = layers.slice(X=array, axis=1, n_outputs=4)
i = layers.sigmoid(group[0])
f = layers.sigmoid(group[1])
o = layers.sigmoid(group[2])
g = layers.sigmoid(group[3])
next_c = f * previous_c + i * g
next_h = o * layers.tanh(next_c)
memory = next_h, next_c
return memory
def lstm(X, n_filters, cache):
WX = cache.setdefault('WX', layers.variable('X_weight'))
WH = cache.setdefault('WH', layers.variable('H_weight'))
bias = cache.setdefault(
'bias', layers.variable('lstm_bias', shape=(1, n_filters * 4, 1, 1)))
network = _rnn_convolution(X, n_filters * 4, WH) + \
(_rnn_convolution(cache['h'], n_filters * 4, WH) if 'h' in cache else 0)
network = layers.broadcast_plus(network, bias)
group = layers.slice(X=network, axis=1, n_outputs=4)
i = layers.sigmoid(group[0])
f = layers.sigmoid(group[1])
o = layers.sigmoid(group[2])
g = layers.tanh(group[3])
cache['c'] = f * cache.get('c', 0) + i * g
cache['h'] = o * layers.tanh(cache['c'])
return cache
def lstm(X, D, cache):
time = cache.setdefault('time', -1)
cache['time'] += 1
WX = cache.setdefault('WX', layers.variable('X_weight'))
WH = cache.setdefault('WH', layers.variable('H_weight'))
bias = cache.setdefault('bias', layers.variable('lstm_bias', shape=(1, D * 4)))
network = _rnn_linearity(X, D * 4, WX) + (_rnn_linearity(cache['h'], D * 4, WH) if 'h' in cache else 0)
network = layers.broadcast_plus(network, bias)
group = layers.slice(X=network, axis=1, n_outputs=4)
i = layers.sigmoid(group[0])
f = layers.sigmoid(group[1])
o = layers.sigmoid(group[2])
g = layers.tanh(group[3])
cache['c'] = f * cache.get('c', 0) + i * g
cache['h'] = o * layers.tanh(cache['c'])
return cache