Edit Question - KnowledgeHub

Title Body

I'm trying to understand how the Python C- Api works, and I want to exchange numpy arrays between Python and a C Extension. So, I started this tutorial: http://dsnra.jpl.nasa.gov/software/Python/numpydoc/numpy-13.html Tried to do the first example there, a C module that calculates the trace of a 2d numpy array, was very neat for me, since I want to do elementary operations in 2d arrays also. #include <Python.h> #include "Numeric/arrayobject.h" #include<stdio.h> int main(){ Py_Initialize(); import_array(); } static char doc[] = "This is the C extension for xor_masking routine"; static PyObject * trace(PyObject *self, PyObject *args) { PyObject *input; PyArrayObject *array; double sum; int i, n; if (!PyArg_ParseTuple(args, "O", &input)) return NULL; array = (PyArrayObject *) PyArray_ContiguousFromObject(input, PyArray_DOUBLE, 2, 2); if (array == NULL) return NULL; n = array->dimensions[0]; if (n > array->dimensions[1]) n = array->dimensions[1]; sum = 0.; for (i = 0; i < n; i++) sum += *(double *)(array->data + i*array->strides[0] + i*array->strides[1]); Py_DECREF(array); return PyFloat_FromDouble(sum); } static PyMethodDef TraceMethods[] = { {"trace", trace, METH_VARARGS, doc}, {NULL, NULL, 0, NULL} }; PyMODINIT_FUNC inittrace(void) { (void) Py_InitModule("trace", TraceMethods); } } The module's name is trace, and it is compiled with the setup.py file: from distutils.core import setup, Extension module = Extension('trace', sources = ['xor_masking.cpp']) setup(name = 'Trace Test', version = '1.0', ext_modules = [module]) The file is compiled, trace.so is imported in IPython, but when I try to use the method trace(), I get a Segmentation Fault, I don't know wh

Tags (comma-separated) Cancel