我正在尝试在tensorflow中实现multidimentional lstm，我使用TensorArray来记住以前的状态，我使用一种复杂的方式来获得两个neigbours状态（上面和左边）。 tf.cond希望存在既有条件并且具有相同数量的输入。这就是为什么我再添加一个cell.zero_state到状态的（最后一个索引+1）。然后我使用函数来获取状态的正确索引。当我试图使用优化器以最小化成本时，我得到了这个错误：
InvalidArgumentError（参见上面的回溯）：TensorArray MultiDimentionalLSTMCell-l1-multi-l1 / state_ta_262 @ gradient：无法 从TensorArray索引809读取，因为它尚未编写 到。
有人能说出如何修复它吗？
Ps：没有优化器就可以了！
class MultiDimentionalLSTMCell(tf.nn.rnn_cell.RNNCell):
"""
Note that state_is_tuple is always True.
"""
def __init__(self, num_units, forget_bias=1.0, activation=tf.nn.tanh):
self._num_units = num_units
self._forget_bias = forget_bias
self._activation = activation
@property
def state_size(self):
return tf.nn.rnn_cell.LSTMStateTuple(self._num_units, self._num_units)
@property
def output_size(self):
return self._num_units
def __call__(self, inputs, state, scope=None):
"""Long short-term memory cell (LSTM).
@param: imputs (batch,n)
@param state: the states and hidden unit of the two cells
"""
with tf.variable_scope(scope or type(self).__name__):
c1,c2,h1,h2 = state
# change bias argument to False since LN will add bias via shift
concat = tf.nn.rnn_cell._linear([inputs, h1, h2], 5 * self._num_units, False)
i, j, f1, f2, o = tf.split(1, 5, concat)
new_c = (c1 * tf.nn.sigmoid(f1 + self._forget_bias) +
c2 * tf.nn.sigmoid(f2 + self._forget_bias) + tf.nn.sigmoid(i) *
self._activation(j))
new_h = self._activation(new_c) * tf.nn.sigmoid(o)
new_state = tf.nn.rnn_cell.LSTMStateTuple(new_c, new_h)
return new_h, new_state
def multiDimentionalRNN_whileLoop(rnn_size,input_data,sh,dims=None,scopeN="layer1"):
"""Implements naive multidimentional recurent neural networks
@param rnn_size: the hidden units
@param input_data: the data to process of shape [batch,h,w,chanels]
@param sh: [heigth,width] of the windows
@param dims: dimentions to reverse the input data,eg.
dims=[False,True,True,False] => true means reverse dimention
@param scopeN : the scope
returns [batch,h/sh[0],w/sh[1],chanels*sh[0]*sh[1]] the output of the lstm
"""
with tf.variable_scope("MultiDimentionalLSTMCell-"+scopeN):
cell = MultiDimentionalLSTMCell(rnn_size)
shape = input_data.get_shape().as_list()
if shape[1]%sh[0] != 0:
offset = tf.zeros([shape[0], sh[0]-(shape[1]%sh[0]), shape[2], shape[3]])
input_data = tf.concat(1,[input_data,offset])
shape = input_data.get_shape().as_list()
if shape[2]%sh[1] != 0:
offset = tf.zeros([shape[0], shape[1], sh[1]-(shape[2]%sh[1]), shape[3]])
input_data = tf.concat(2,[input_data,offset])
shape = input_data.get_shape().as_list()
h,w = int(shape[1]/sh[0]),int(shape[2]/sh[1])
features = sh[1]*sh[0]*shape[3]
batch_size = shape[0]
x = tf.reshape(input_data, [batch_size,h,w, features])
if dims is not None:
x = tf.reverse(x, dims)
x = tf.transpose(x, [1,2,0,3])
x = tf.reshape(x, [-1, features])
x = tf.split(0, h*w, x)
sequence_length = tf.ones(shape=(batch_size,), dtype=tf.int32)*shape[0]
inputs_ta = tf.TensorArray(dtype=tf.float32, size=h*w,name='input_ta')
inputs_ta = inputs_ta.unpack(x)
states_ta = tf.TensorArray(dtype=tf.float32, size=h*w+1,name='state_ta',clear_after_read=False)
outputs_ta = tf.TensorArray(dtype=tf.float32, size=h*w,name='output_ta')
states_ta = states_ta.write(h*w, tf.nn.rnn_cell.LSTMStateTuple(tf.zeros([batch_size,rnn_size], tf.float32),
tf.zeros([batch_size,rnn_size], tf.float32)))
def getindex1(t,w):
return tf.cond(tf.less_equal(tf.constant(w),t),
lambda:t-tf.constant(w),
lambda:tf.constant(h*w))
def getindex2(t,w):
return tf.cond(tf.less(tf.constant(0),tf.mod(t,tf.constant(w))),
lambda:t-tf.constant(1),
lambda:tf.constant(h*w))
time = tf.constant(0)
def body(time, outputs_ta, states_ta):
constant_val = tf.constant(0)
stateUp = tf.cond(tf.less_equal(tf.constant(w),time),
lambda: states_ta.read(getindex1(time,w)),
lambda: states_ta.read(h*w))
stateLast = tf.cond(tf.less(constant_val,tf.mod(time,tf.constant(w))),
lambda: states_ta.read(getindex2(time,w)),
lambda: states_ta.read(h*w))
currentState = stateUp[0],stateLast[0],stateUp[1],stateLast[1]
out , state = cell(inputs_ta.read(time),currentState)
outputs_ta = outputs_ta.write(time,out)
states_ta = states_ta.write(time,state)
return time + 1, outputs_ta, states_ta
def condition(time,outputs_ta,states_ta):
return tf.less(time , tf.constant(h*w))
result , outputs_ta, states_ta = tf.while_loop(condition, body, [time,outputs_ta,states_ta])
outputs = outputs_ta.pack()
states = states_ta.pack()
y = tf.reshape(outputs, [h,w,batch_size,rnn_size])
y = tf.transpose(y, [2,0,1,3])
if dims is not None:
y = tf.reverse(y, dims)
return y
def tanAndSum(rnn_size,input_data,scope):
outs = []
for i in range(2):
for j in range(2):
dims = [False]*4
if i!=0:
dims[1] = True
if j!=0:
dims[2] = True
outputs = multiDimentionalRNN_whileLoop(rnn_size,input_data,[2,2],
dims,scope+"-multi-l{0}".format(i*2+j))
outs.append(outputs)
outs = tf.pack(outs, axis=0)
mean = tf.reduce_mean(outs, 0)
return tf.nn.tanh(mean)
graph = tf.Graph()
with graph.as_default():
input_data = tf.placeholder(tf.float32, [20,36,90,1])
#input_data = tf.ones([20,36,90,1],dtype=tf.float32)
sh = [2,2]
out1 = tanAndSum(20,input_data,'l1')
out = tanAndSum(25,out1,'l2')
cost = tf.reduce_mean(out)
optimizer = tf.train.AdamOptimizer(learning_rate=0.001).minimize(cost)
#out = multiDimentionalRNN_raw_rnn(2,input_data,sh,dims=[False,True,True,False],scopeN="layer1")
#cell = MultiDimentionalLSTMCell(10)
#out = cell.zero_state(2, tf.float32).c
with tf.Session(graph=graph) as session:
tf.global_variables_initializer().run()
ou,k,_ = session.run([out,cost,optimizer],{input_data:np.ones([20,36,90,1],dtype=np.float32)})
print(ou.shape)
print(k)
答案 0 :(得分：3)
您应该在while循环调用中添加参数parallel_iterations=1。
如：
result, outputs_ta, states_ta = tf.while_loop(
condition, body, [time,outputs_ta,states_ta], parallel_iterations=1)
这是必需的，因为在体内，您在同一张量阵列（states_ta）上执行读写操作。在并行循环执行的情况下（parallel_iterations＆gt; 1），某些线程可能会尝试从tensorArray读取信息，而不是另一个线程写入的信息。
我已经在tensorflow 0.12.1上使用parallel_iterations = 1来测试您的代码段，并且它按预期工作。