[Boost-commit] svn:boost r73849 - sandbox/numpy/libs/numpy/example

Subject: [Boost-commit] svn:boost r73849 - sandbox/numpy/libs/numpy/example
From: ankitdaf_at_[hidden]
Date: 2011-08-17 14:25:45

Author: ankitdaf
Date: 2011-08-17 14:25:44 EDT (Wed, 17 Aug 2011)
New Revision: 73849
URL: http://svn.boost.org/trac/boost/changeset/73849

Log:
Added example for ufunc
Added:
   sandbox/numpy/libs/numpy/example/ufunc.cpp   (contents, props changed)
Text files modified: 
   sandbox/numpy/libs/numpy/example/Jamfile |     1 +                                       
   1 files changed, 1 insertions(+), 0 deletions(-)

Modified: sandbox/numpy/libs/numpy/example/Jamfile
==============================================================================
--- sandbox/numpy/libs/numpy/example/Jamfile	(original)
+++ sandbox/numpy/libs/numpy/example/Jamfile	2011-08-17 14:25:44 EDT (Wed, 17 Aug 2011)
@@ -24,3 +24,4 @@
 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 ;

Added: sandbox/numpy/libs/numpy/example/ufunc.cpp
==============================================================================
--- (empty file)
+++ sandbox/numpy/libs/numpy/example/ufunc.cpp	2011-08-17 14:25:44 EDT (Wed, 17 Aug 2011)
@@ -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 <boost/numpy.hpp>
+#include <iostream>
+
+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, boost::shared_ptr<UnarySquare> >("UnarySquare")
+    .def("__call__", np::unary_ufunc<UnarySquare>::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 <char const * > (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<int>() , p::make_tuple(4), p::make_tuple(4), p::object());
+  // Print out the demo array
+  std::cout << "Demo array is " << p::extract <char const * > (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 <char const * > (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 <char const * > (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 <char const * > (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, boost::shared_ptr<BinarySquare> >("BinarySquare")
+    .def("__call__", np::binary_ufunc<BinarySquare>::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 <char const * > (p::str(demo_array)) << std::endl << p::extract <char const * > (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 <char const * > (p::str(result_array)) << std::endl ; 
+}
+