Tensorflow basic structure

Javascript learned or should xml students a better understanding of the DOM model,
DOM model, all things are seen as Node element,
but there are different sub-Node element earth elements, such as document, element, attribute, etc.,
and is very similar to DOM , tensorflow all elements called grarh elements, together constituting a gragh,
and specifically, there are the following several basic elements:
tensor (tensor):
  as already said.
Variable:
  also known weight (weight), parameter (w), there are between two nodes connected to such a parameter,
  the future of training is to find the right parameters.
  general directly to all the parameters between the two layers is written inside a matrix,
  the number of rows to the starting point node layer number, the number of columns for the end layer nodes.
placeholder:
  a lot of people called placeholders, in fact, the input vector variables,
  like function definitions, wrote parameter list parameter.
  the main features of the number of rows in a statement here matrix future (Shape),
  such as: X = tf.placeholder (tf.float32, Shape = (None, 2))
OP:
  node acquires tensor (or not to acquire tensor), calculated tensor,
  described between tensor computing relationship, it is the real structure of the network.
  general computing section Such as:
    A = tf.matmul (X, W1)
    Y = tf.matmul (A, w2 of)
  There are special types of nodes (I've seen):
  1. loss function:
    such as: Loss = tf.reduce_mean (tf.square (Y_-Y))
  2. Reverse propagation:
    train_step = tf.train.GradientDescentOptimizer (from 0.001) .minimize (Loss)
    train_step = tf.train.MomentumOptimizer (0.0001,0.99) .minimize (Loss)
    train_step = tf.train.AdamOptimizer (from 0.0001) .minimize (Loss)
    (in practice only one is enough)
  3. variables initialization:
    Yes, you read right, variable initialization even be considered graph elements,
    and then they have to initialize before you can "run" behind the node
    init_op = tf.global_variables_initializer ()
    sess.run (init_op)
  4. counter:
    current level I see I do not know, do not write.

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Origin blog.csdn.net/realliyuhao/article/details/104117928