我正在寻找一种方法来快速更改Jupyter中交互式会话中的图形，以便测试不同的结构。最初我想简单地删除现有变量并使用不同的初始化程序重新创建它们。这似乎不可能[1]。
然后我找到了[2]并且现在正试图简单地丢弃并重新创建默认图形。但这似乎不起作用。这就是我的工作：
一个。开始会议
import tensorflow as tf
import math
sess = tf.InteractiveSession()
湾在默认图表中创建变量
IMAGE_PIXELS = 32 * 32
HIDDEN1 = 200
BATCH_SIZE = 100
NUM_POINTS = 30
images_placeholder = tf.placeholder(tf.float32, shape=(BATCH_SIZE, IMAGE_PIXELS))
points_placeholder = tf.placeholder(tf.float32, shape=(BATCH_SIZE, NUM_POINTS))
# Hidden 1
with tf.name_scope('hidden1'):
weights_init = tf.truncated_normal([IMAGE_PIXELS, HIDDEN1], stddev=1.0 / math.sqrt(float(IMAGE_PIXELS)))
weights = tf.Variable(weights_init, name='weights')
biases_init = tf.zeros([HIDDEN1])
biases = tf.Variable(biases_init, name='biases')
hidden1 = tf.nn.relu(tf.matmul(images_placeholder, weights) + biases)
℃。使用变量
# Add the variable initializer Op.
init = tf.initialize_all_variables()
# Run the Op to initialize the variables.
sess.run(init)
d。重置图表
tf.reset_default_graph()
即重新创建变量
with tf.name_scope('hidden1'):
weights = tf.get_variable(name='weights', shape=[IMAGE_PIXELS, HIDDEN1],
initializer=tf.contrib.layers.xavier_initializer())
biases_init = tf.zeros([HIDDEN1])
biases = tf.Variable(biases_init, name='biases')
hidden1 = tf.nn.relu(tf.matmul(images_placeholder, weights) + biases)
然而，我得到一个例外（见下文）。所以我的问题是：是否有可能重置/删除图表并像以前一样重新创建它？如果是这样，怎么样？
欣赏任何指针。
TIA，
ValueError Traceback (most recent call last)
<ipython-input-5-e98a82c45473> in <module>()
5 biases_init = tf.zeros([HIDDEN1])
6 biases = tf.Variable(biases_init, name='biases')
----> 7 hidden1 = tf.nn.relu(tf.matmul(images_placeholder, weights) + biases)
8
/home/hmf/my_py3/lib/python3.4/site-packages/tensorflow/python/ops/math_ops.py in matmul(a, b, transpose_a, transpose_b, a_is_sparse, b_is_sparse, name)
1323 A `Tensor` of the same type as `a`.
1324 """
-> 1325 with ops.op_scope([a, b], name, "MatMul") as name:
1326 a = ops.convert_to_tensor(a, name="a")
1327 b = ops.convert_to_tensor(b, name="b")
/usr/lib/python3.4/contextlib.py in __enter__(self)
57 def __enter__(self):
58 try:
---> 59 return next(self.gen)
60 except StopIteration:
61 raise RuntimeError("generator didn't yield") from None
/home/hmf/my_py3/lib/python3.4/site-packages/tensorflow/python/framework/ops.py in op_scope(values, name, default_name)
4014 ValueError: if neither `name` nor `default_name` is provided.
4015 """
-> 4016 g = _get_graph_from_inputs(values)
4017 n = default_name if name is None else name
4018 if n is None:
/home/hmf/my_py3/lib/python3.4/site-packages/tensorflow/python/framework/ops.py in _get_graph_from_inputs(op_input_list, graph)
3812 graph = graph_element.graph
3813 elif original_graph_element is not None:
-> 3814 _assert_same_graph(original_graph_element, graph_element)
3815 elif graph_element.graph is not graph:
3816 raise ValueError(
/home/hmf/my_py3/lib/python3.4/site-packages/tensorflow/python/framework/ops.py in _assert_same_graph(original_item, item)
3757 if original_item.graph is not item.graph:
3758 raise ValueError(
-> 3759 "%s must be from the same graph as %s." % (item, original_item))
3760
3761
ValueError: Tensor("weights:0", shape=(1024, 200), dtype=float32_ref) must be from the same graph as Tensor("Placeholder:0", shape=(100, 1024), dtype=float32).`
答案 0 :(得分：11)
重置默认图表时，不会删除之前创建的张量。调用tf.reset_default_graph()时，会创建一个新图并设置为默认值。
这是一个例子来说明：
x = tf.constant(1)
print tf.get_default_graph() == x.graph # prints True
tf.reset_default_graph()
print tf.get_default_graph() == x.graph # prints False
您所犯的错误表明两个张量必须来自同一个图表，这意味着您仍在使用上一个图表和当前默认图表中的一些张量。
简单的解决方法是再次创建两个占位符images_placeholder和points_placeholder