Simple SWIG/numpy example

setup.py

from distutils.core import setup, Extension
import numpy
import os

os.environ['CC'] = 'g++';
setup(name='matt_simple_test', version='1.0', ext_modules =[Extension('_simple',
 ['simple.cc', 'simple.i'], include_dirs = [numpy.get_include(),'.'])])

simple.cc

double dot(int n, double *a, int m, double *b){
  double sum = 0.0;
  for (int i=0; i<n; i++){
    sum += a[i]*b[i];
  }
  return sum;
}

void create_list(int size, double *arr){
  for (int i=0; i<size; i++)
    arr[i] = i;
}

simple.h

double dot(int n, double *a, int m, double *b);
void create_list(int size, double *arr);

simple.h

double dot(int n, double *a, int m, double *b);
void create_list(int size, double *arr);

simple.i

%module simple
%{
  #define SWIG_FILE_WITH_INIT
  #include "simple.h"
%}

%include "numpy.i"
%init %{
import_array();
%}

%apply (int DIM1, double* INPLACE_ARRAY1) {(int n0, double *a0)};
%apply (int DIM1, double* IN_ARRAY1) {(int n, double *a), (int m, double *b)};
%apply (int DIM1, double* ARGOUT_ARRAY1) {(int size, double *arr)};
%include "simple.h"

test.py

import simple
import numpy
from time import time

a = simple.create_list(1000000)

numpy_start = time()
print "Numpy says:", numpy.dot(a,a)
numpy_end = time()

swig_start = time()
print "SWIG says:", simple.dot(a,a)
swig_end = time()

print "Time of numpy:", (numpy_end-numpy_start)
print "Time of SWIG:", (swig_end-swig_start)