C++ API

The C++ API of bob.learn.linear allows users to leverage from automatic converters for classes in bob.learn.linear. To use the C API, clients should first, include the header file <bob.learn.linear/api.h> on their compilation units and then, make sure to call once import_bob_learn_linear() at their module instantiation, as explained at the Python manual.

Here is a dummy C example showing how to include the header and where to call the import function:

#include <bob.learn.linear/api.h>

PyMODINIT_FUNC initclient(void) {

  PyObject* m Py_InitModule("client", ClientMethods);

  if (!m) return 0;

  if (import_bob_blitz() < 0) return 0;
  if (import_bob_io() < 0) return 0;
  if (import_bob_learn_activation() < 0) return 0;

  return m;

}

Note

The include directory can be discovered using bob.learn.linear.get_include().

Activation Functors

type PyBobMachineActivationObject

The pythonic object representation for a bob::machine::Activation object. It is the base class of all activation functors available in Bob. In C/C++ code, we recommend you only manipulate objects like this to keep your code agnostic to the activation type being used.

typedef struct {
  PyObject_HEAD
  bob::machine::Activation* base;
} PyBobMachineActivationObject;

bob::machine::Activation* base

A pointer to the activation functor virtual implementation.

int PyBobMachineActivation_Check(PyObject* o)

Checks if the input object o is a PyBobMachineActivationObject. Returns 1 if it is, and 0 otherwise.

Note

Other object definitions exist for each of the specializations for activation functors found in Bob. They are exported through the module C-API, but we don’t recommend using them since you’d loose generality. In case you do absolutely need to use any of these derivations, they have all the same object configuration:

typedef struct {
  PyBobMachineActivationObject parent;
  bob::machine::<Subtype>Activation* base;
} PyBobMachine<Subtype>ActivationObject;

Presently, <Subtype> can be one of:

• Identity
• Linear
• Logistic
• HyperbolicTangent
• MultipliedHyperbolicTangent

Type objects are also named consistently like PyBobMachine<Subtype>_Type.