Merge NumPy extension from https://github.com/ndarray/Boost.NumPy/.

example/numpy/dtype.cpp

@@ -0,0 +1,49 @@
+// 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/numpy.hpp>
+#include <iostream>
+
+namespace p = boost::python;
+namespace np = boost::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);
+
+}