EQ2EMu/EQ2/source/depends/boost_1_72_0/libs/python/example/numpy/dtype.cpp

// Copyright Ankit Daftery 2011-2012.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)

/**
 *  @brief An example to show how to create ndarrays with built-in python data types, and extract
 *         the types and values of member variables
 *
 *  @todo Add an example to show type conversion.
 *        Add an example to show use of user-defined types
 *        
 */

#include <boost/python/numpy.hpp>
#include <iostream>

namespace p = boost::python;
namespace np = boost::python::numpy;

int main(int argc, char **argv)
{
  // Initialize the Python runtime.
  Py_Initialize();
  // Initialize NumPy
  np::initialize();
  // Create a 3x3 shape...
  p::tuple shape = p::make_tuple(3, 3);
  // ...as well as a type for C++ double
  np::dtype dtype = np::dtype::get_builtin<double>();
  // Construct an array with the above shape and type
  np::ndarray a = np::zeros(shape, dtype);
  // Print the array
  std::cout << "Original array:\n" << p::extract<char const *>(p::str(a)) << std::endl;
  // Print the datatype of the elements
  std::cout << "Datatype is:\n" << p::extract<char const *>(p::str(a.get_dtype())) << std::endl ;
  // Using user defined dtypes to create dtype and an array of the custom dtype
  // First create a tuple with a variable name and its dtype, double, to create a custom dtype
  p::tuple for_custom_dtype = p::make_tuple("ha",dtype) ;
  // The list needs to be created, because the constructor to create the custom dtype
  // takes a list of (variable,variable_type) as an argument
  p::list list_for_dtype ;
  list_for_dtype.append(for_custom_dtype) ;
  // Create the custom dtype
  np::dtype custom_dtype = np::dtype(list_for_dtype) ;
  // Create an ndarray with the custom dtype
  np::ndarray new_array = np::zeros(shape,custom_dtype);

}