Thanks for the answers, Chris. A few comments and questions beyond what I asked and you answered:
--- Christopher Barker <[EMAIL PROTECTED]> wrote: > Lou, > > This type of question is best posed on the numpy > list: > > http://projects.scipy.org/mailman/listinfo/numpy-discussion Ah, yet another mailing list to join. Sigh. :-) > Lou Pecora wrote: > > >> PyArrayObject *mat; > >> PyArg_ParseTuple(args, "O!", &PyArray_Type, > &mat); > > If you do this, you then need to check and see if > the array that got > passed in has the properties you want: size, shape, > type. I do, but I don't know how to check in Python for contiguous. I will search for that. Should be a way. > > >> PyObject *Pymat; > >> PyArrayObject *mat; > >> PyArg_ParseTuple(args, "O", &Pymat); > >> > mat=PyArray_ContiguousFromObject(objin,NPY_DOUBLE, > >> 2,2); > > I've always used PyArray_ContiguousFromObject, > because then it does all > the checking for me, and it allows my code to accept > anything that can > by turned into a numpy array. Got it. That's what I suspected. > >> The latter appears to have the constraint that > the > >> array be contiguous. Or is that an illusion and > >> it's > >> saying it _expects_ a Python object that has > >> contiguous data? > > What it does is convert whatever you pass in to a > Contiguous array. If > it already is a contiguous array, then it returns > itself (I think -- > check the docs). There is probably something like: > > PyArray_FromObject > > That does not guarantee contiguous, if you don't > need that. That can lead to a problem. If I have a C extension in which I expect to operate on the array data in place, then passing a non-contiguous array will cause a new data set to be developed (new memory, I would assume) and the original array would not be changed in place by my C operations. Then I have a problem. The original array is unchanged, but I assume it has been changed. In this case I would want a check on whether the input array is contiguous and an exception raised if not ... or something to say there's a data-structure problem. -- Lou Pecora My views are my own. ____________________________________________________________________________________ Yahoo! Music Unlimited Access over 1 million songs. http://music.yahoo.com/unlimited _______________________________________________ Pythonmac-SIG maillist - Pythonmac-SIG@python.org http://mail.python.org/mailman/listinfo/pythonmac-sig
