Scope

tensorflow C++ API

tensorflow::Scope

A Scope object represents a set of related TensorFlow ops that have the same properties such as a common name prefix.

Summary

A Scope object is a container for TensorFlow Op properties. Op constructors get a Scope object as a mandatory first argument and the constructed op acquires the properties in the object.

A simple example:

using namespace ops;

Scope root =Scope::NewRootScope();
auto c1 =Const(root,{{1,1}});
auto m =MatMul(root, c1,{{41},{1}});
GraphDef gdef;
Status s = root.ToGraphDef(&gdef);
if(!s.ok()){...}

Scope hierarchy:

The Scope class provides various With<> functions that create a new scope. The new scope typically has one property changed while other properties are inherited from the parent scope. NewSubScope(name) method appendsnameto the prefix of names for ops created within the scope, and WithOpName() changes the suffix which otherwise defaults to the type of the op.

Name examples:

Scope root =Scope::NewRootScope();
Scope linear = root.NewSubScope("linear");
// W will be named "linear/W"
auto W =Variable(linear.WithOpName("W"),
                 {2,2}, DT_FLOAT);
// b will be named "linear/b"
auto b =Variable(linear.WithOpName("b"),{2}, DT_FLOAT);
auto x =Const(linear,{...}); // name: "linear/Const"
auto m =MatMul(linear, x, W); // name: "linear/MatMul"
auto r =BiasAdd(linear, m, b); // name: "linear/BiasAdd"

Scope lifetime:

A new scope is created by calling Scope::NewRootScope. This creates some resources that are shared by all the child scopes that inherit from this scope, directly or transitively. For instance, a new scope creates a new Graph object to which operations are added when the new scope or its children are used by an Op constructor. The new scope also has a Status object which will be used to indicate errors by Op-constructor functions called on any child scope. The Op-constructor functions have to check the scope's status by calling the ok() method before proceeding to construct the op.

Thread safety:

A Scope object is NOT thread-safe. Threads cannot concurrently call op-constructor functions on the same Scope object.

Scope block

Source link :https://github.com/EXPNUNI/enuSpaceTensorflow/blob/master/enuSpaceTensorflow/tf_core.cpp

Argument: There is no scope block. The picture file is a scope.