I need some help regarding passing C array to python(numpy). I have 2d array of doubles NumRows x NumInputs, it seems that PyArray_SimpleNewFromData does not convert it right way - it is hard to see because debugger does not show much, only pointers.

What would be the right way to pass 2 dimensional array ?

int NumRows = X_test.size();
int NumInputs = X_test_row.size();double **X_test2 = new double*[NumRows];
for(int i = 0; i < NumRows; ++i) 
{X_test2[i] = new double[NumInputs];
}for(int r = 0; r < NumRows; ++r) 
{for(int c = 0; c < NumInputs; ++c) {X_test2[r][c] = X_test[r][c];}
}const char *ScriptFName = "100-ABN-PREDICT";
char *FunctionName=NULL;FunctionName="PredictGBC_DBG"; npy_intp Dims[2];
Dims[0]= NumRows;
Dims[1] = NumInputs;PyObject *ArgsArray;
PyObject *pName, *pModule, *pDict, *pFunc, *pValue, *pArgs;int row, col, rows, cols, size, type;const double* outArray;
double ArrayItem;//===================Py_Initialize();pName = PyBytes_FromString(ScriptFName);pModule = PyImport_ImportModule(ScriptFName);if (pModule != NULL)
{import_array(); // Required for the C-APIArgsArray = PyArray_SimpleNewFromData (2, Dims, NPY_DOUBLE, X_test2);//SOMETHING WRONG pDict = PyModule_GetDict(pModule);pArgs = PyTuple_New (1);PyTuple_SetItem (pArgs, 0, ArgsArray);pFunc = PyDict_GetItemString(pDict, FunctionName);if (pFunc && PyCallable_Check(pFunc)){pValue = PyObject_CallObject(pFunc, pArgs);//CRASHING HEREif (pValue != NULL) {rows = PyArray_DIM(pValue, 0);cols = PyArray_DIM(pValue, 1);size = PyArray_SIZE(pValue);type = PyArray_TYPE(pValue);// get direct access to the array data//PyObject* m_obj;outArray = static_cast<const double*>(PyArray_DATA(pValue));for (row=0; row < rows; row++) {ArrayItem = outArray[row];y_pred.push_back(ArrayItem);}}else {y_pred.push_back(EMPTY_VAL);}}else {PyErr_Print();}//pFunc && PyCallable_Check(pFunc)}//(pModule!=NULL
else
{PyErr_SetString(PyExc_TypeError, "Cannot call function ?!");PyErr_Print();
}Py_DECREF(pValue);
Py_DECREF(pFunc);Py_DECREF(ArgsArray);  
Py_DECREF(pModule);
Py_DECREF(pName);Py_Finalize (); 

You'll have to copy your data to a contiguous block of memory. To represent a 2d array, numpy does not use an array of pointers to 1d arrays. Numpy expects the array to be stored in a contiguous block of memory, in (by default) row major order.

If you create your array using PyArray_SimpleNew(...), numpy allocates the memory for you. You have to copy X_test2 to this array, using, say, std::memcpy or std::copy in a loop over the rows.

That is, change this:

ArgsArray = PyArray_SimpleNewFromData (2, Dims, NPY_DOUBLE, X_test2);//SOMETHING WRONG 

to something like this:

// PyArray_SimpleNew allocates the memory needed for the array.
ArgsArray = PyArray_SimpleNew(2, Dims, NPY_DOUBLE);// The pointer to the array data is accessed using PyArray_DATA()
double *p = (double *) PyArray_DATA(ArgsArray);// Copy the data from the "array of arrays" to the contiguous numpy array.
for (int k = 0; k < NumRows; ++k) {memcpy(p, X_test2[k], sizeof(double) * NumInputs);p += NumInputs;
}

(It looks like X_test2 is a copy of X_test, so you might want to modify the above code to copy directly from X_test to the numpy array.)