[Numpy-discussion] Re: Numpy-discussion digest, Vol 1 #50 - 2 msgs

[Vanroose W. <van...@ru...>]

Dear Travis Oliphant,

        The pointer  result->data is of  type   (char *).    So I still have
to do a cast

        data = (Py_complex *)result->data;

Best Wishes
Wim Vanroose

Travis Oliphant wrote:

> Yes, you can create the array, point a pointer to "result->data" and fill
> it in.  Internally, when the array is created an equivalent malloc is
> performed.
>
> I've changed your code below to eliminate the unecessary copying.
> >
> >
> > static PyObject* matrix(PyObject *self, PyObject *args){
> >   double x,y;
> >   int size;
> >   int M,n,m;
> >   PyArrayObject *result;
> >   int dimensions[2];
> >   Py_complex *data;
> >   Py_complex p;
> >   if(!PyArg_ParseTuple(args,"idd",&M,&x,&y))
> >     return NULL;
> >   dimensions[0] = M;
> >   dimensions[1] = M;
>
> >   result = (PyArrayObject
> > *)PyArray_FromDims(2,dimensions,PyArray_CDOUBLE);
>
> >   data = result->data;
> >   for(n=0;n < M;n++){
> >     for(m=0; m<M; m++){
> >       p.real=x;
> >       p.imag=y;
> >       data[n*M+m] = p;
> >     }
> >   }
>
> >   return PyArray_Return(result);
> >   free(data);
> > }
> >
>
> Welcome to the wonderful world of NumPy.
>
> -Travis