diff --git a/libs/numpy/example/Jamfile b/libs/numpy/example/Jamfile index 5aa47d99..1cab0490 100644 --- a/libs/numpy/example/Jamfile +++ b/libs/numpy/example/Jamfile @@ -24,3 +24,4 @@ exe dtype : dtype.cpp ../src//boost_numpy boost_python /python//python ; exe ndarray : ndarray.cpp ../src//boost_numpy boost_python /python//python ; exe hybrid : hybrid.cpp ../src//boost_numpy boost_python /python//python ; exe fromdata : fromdata.cpp ../src//boost_numpy boost_python /python//python ; +exe ufunc : ufunc.cpp ../src//boost_numpy boost_python /python//python ; diff --git a/libs/numpy/example/ufunc.cpp b/libs/numpy/example/ufunc.cpp new file mode 100644 index 00000000..a751cdcc --- /dev/null +++ b/libs/numpy/example/ufunc.cpp @@ -0,0 +1,81 @@ +/** + * @brief An example to demonstrate use of universal functions or ufuncs + * + * + * @todo Calling the overloaded () operator is in a roundabout manner, find a simpler way + * None of the methods like np::add, np::multiply etc are supported as yet + */ + +#include +#include + +namespace p = boost::python; +namespace np = boost::numpy; + + +// Create the structs necessary to implement the ufuncs +// The typedefs *must* be made + +struct UnarySquare +{ + typedef double argument_type; + typedef double result_type; + + double operator()(double r) const { return r * r;} +}; + +struct BinarySquare +{ + typedef double first_argument_type; + typedef double second_argument_type; + typedef double result_type; + + double operator()(double a,double b) const { return (a*a + b*b) ; } +}; + +int main(int argc, char **argv) +{ + // Initialize the Python runtime. + Py_Initialize(); + // Initialize NumPy + np::initialize(); + // Expose the struct UnarySquare to Python as a class, and let ud be the class object + p::object ud = p::class_ >("UnarySquare") + .def("__call__", np::unary_ufunc::make()); + // Let inst be an instance of the class ud + p::object inst = ud(); + // Use the "__call__" method to call the overloaded () operator and print the value + std::cout << "Square of unary scalar 1.0 is " << p::extract (p::str(inst.attr("__call__")(1.0))) << std::endl ; + // Create an array in C++ + int arr[] = {1,2,3,4} ; + // ..and use it to create the ndarray in Python + np::ndarray demo_array = np::from_data(arr, np::dtype::get_builtin() , p::make_tuple(4), p::make_tuple(4), p::object()); + // Print out the demo array + std::cout << "Demo array is " << p::extract (p::str(demo_array)) << std::endl ; + // Call the "__call__" method to perform the operation and assign the value to result_array + p::object result_array = inst.attr("__call__")(demo_array) ; + // Print the resultant array + std::cout << "Square of demo array is " << p::extract (p::str(result_array)) << std::endl ; + // Lets try the same with a list + p::list li ; + li.append(3); + li.append(7); + // Print out the demo list + std::cout << "Demo list is " << p::extract (p::str(li)) << std::endl ; + // Call the ufunc for the list + result_array = inst.attr("__call__")(li) ; + // And print the list out + std::cout << "Square of demo list is " << p::extract (p::str(result_array)) << std::endl ; + // Now lets try Binary ufuncs + // Expose the struct BinarySquare to Python as a class, and let ud be the class object + ud = p::class_ >("BinarySquare") + .def("__call__", np::binary_ufunc::make()); + // Again initialise inst as an instance of the class ud + inst = ud(); + // Print the two input listsPrint the two input lists + std::cout << "The two input list for binary ufunc are " << std::endl << p::extract (p::str(demo_array)) << std::endl << p::extract (p::str(demo_array)) << std::endl ; + // Call the binary ufunc taking demo_array as both inputs + result_array = inst.attr("__call__")(demo_array,demo_array) ; + std::cout << "Square of list with binary ufunc is " << p::extract (p::str(result_array)) << std::endl ; +} +