See the guide: Building Graphs > Defining new operations
Specifies that ops of type
op_type is not differentiable.
This function should not be used for operations that have a well-defined gradient that is not yet implemented.
This function is only used when defining a new op type. It may be
used for ops such as
tf.size() that are not differentiable. For
The gradient computed for 'op_type' will then propagate zeros.
For ops that have a well-defined gradient but are not yet implemented, no declaration should be made, and an error must be thrown if an attempt to request its gradient is made.
op_type: The string type of an operation. This corresponds to the
OpDef.namefield for the proto that defines the operation.
op_typeis not a string.