Variables

How do we write this all out in TensorFlow code? Let's start by creating our weights and biases. In TensorFlow, if we want to create some Tensors that can be manipulated by our code, then we need to use TensorFlow variables. TensorFlow variables are instances of the tf.Variable class. A tf.Variable class represents a tf.Tensor object that can have its values changed by running TensorFlow operations on it. Variables are Tensor-like objects, so they can be passed around in the same ways Tensors can and any operation that can be used with a Tensor can be used with a variable.

To create a variable, we can use tf.get_variable(). When you call this function, you must supply a name for your variable. This function will first check that there is no other variable with the same name already on the graph, and if there isn't, then it will create and add a new one to the TensorFlow graph.

You must also specify the shape that you want your variable to have, or alternatively, you can initialize your variable using a tf.constant Tensor. The variable will take the value of your constant Tensor and the shape will be automatically inferred. For example, the following will produce a 1x2 Tensor containing the values 21 and 25:

my_variable = tf.get_variable(name= "my_variable", initializer=tf.constant([21, 25]))