A unary_ufunc is a struct used as an intermediate step to broadcast a single argument so that a C++ function can be converted to a ufunc like function
<boost/python/numpy/ufunc.hpp> contains the unary_ufunc structure definitions
namespace boost
{
namespace python
{
namespace numpy
{
template <typename TUnaryFunctor,
typename TArgument=typename TUnaryFunctor::argument_type,
typename TResult=typename TUnaryFunctor::result_type>
struct unary_ufunc
{
static object call(TUnaryFunctor & self,
object const & input,
object const & output) ;
static object make();
};
}
}
}
struct example_unary_ufunc
{
typedef any_valid_type argument_type;
typedef any_valid_type result_type;
};
| Requirements: | The any_valid type must be defined using typedef as a valid C++ type in order to use the struct methods correctly |
|---|
| Note: | The struct must be exposed as a Python class, and an instance of the class must be created to use the call method corresponding to the __call__ attribute of the Python object |
|---|
template <typename TUnaryFunctor,
typename TArgument=typename TUnaryFunctor::argument_type,
typename TResult=typename TUnaryFunctor::result_type>
static object call(TUnaryFunctor & self,
object const & input,
object const & output);
| Requires: | Typenames TUnaryFunctor and optionally TArgument for argument type and TResult for result type |
|---|
| Effects: | Passes a Python object to the underlying C++ functor after broadcasting its arguments |
|---|
template <typename TUnaryFunctor,
typename TArgument=typename TUnaryFunctor::argument_type,
typename TResult=typename TUnaryFunctor::result_type>
static object make();
| Requires: | Typenames TUnaryFunctor and optionally TArgument for argument type and TResult for result type |
|---|
| Returns: | A Python function object to call the overloaded () operator in the struct (in typical usage) |
|---|
namespace p = boost::python;
namespace np = boost::python::numpy;
struct UnarySquare
{
typedef double argument_type;
typedef double result_type;
double operator()(double r) const { return r * r;}
};
p::object ud = p::class_<UnarySquare, boost::shared_ptr<UnarySquare> >("UnarySquare").def("__call__", np::unary_ufunc<UnarySquare>::make());
p::object inst = ud();
std::cout << "Square of unary scalar 1.0 is " << p::extract <char const * > (p::str(inst.attr("__call__")(1.0))) << std::endl ;
