Mailman 3 March 2012 - NumPy-Discussion

YouTrack testbed
by Maggie Mari April 18, 2012

April 18, 2012

Hello, everyone. I work with Travis at Continuum, and he asked me to setup a YouTrack server that everyone is welcome to play around with. There is a test project currently set up, with some fake tickets. Here is the address: http://ec2-107-21-65-210.compute-1.amazonaws.com:8011/issues It's running on an AWS micro instance, so it might be slow at the moment. Any feedback or comments would be welcome. Maggie

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Testsuite fails with Python 2.7.3rc1 and 3.2.3rc1 (Debian)
by Sandro Tosi April 8, 2012

April 8, 2012

Hello, I've reported http://projects.scipy.org/numpy/ticket/2085 and Ralf asked for bringing that up here: is anyone able to replicate the problem described in that ticket? The debian bug tracking the problem is: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=664672 Cheers, -- Sandro Tosi (aka morph, morpheus, matrixhasu) My website: http://matrixhasu.altervista.org/ Me at Debian: http://wiki.debian.org/SandroTosi

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empty chararrays (ticket 1948)
by Ralf Gommers April 7, 2012

April 7, 2012

Hi, In ticket 1948 a backwards compatibility issue with chararray is reported. Indexing a chararray with [] or a bool array of False used to return [] in numpy 1.2.1 (consistent with ndarray behavior), but now returns an empty string. Unfortunately this changed behavior has been present for the 1.5.x and 1.6.x releases. So the question is if this should be changed back or not? The change was likely unintentional; there's no test for it. Ralf

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Trac configuration tweak
by Pauli Virtanen April 3, 2012

April 3, 2012

Hi, I moved projects.scipy.org Tracs to run on mod_python (instead of CGI), in order to try to combat the present performance issues. Let's see if this helps with the "database is locked" problem. Please drop me a message if something stops working. Pauli

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Style for pad implementation in 'pad' namespace or functions under np.lib
by Tim Cera April 3, 2012

April 3, 2012

I have been developing a set of pad functions to pad arrays in different ways. Really close to having it accepted into numpy, but I want to revisit an implementation issue that I have become worried about. Should these functions be collected into a 'pad' namespace or put raw into np.lib? Do I really care about this? Not really since it isn't a utility issue, but I contend that it would look better to pull these functions into their own namespace. Is there a consensus? The current pull request: https://github.com/numpy/numpy/pull/242 Kindest regards, Tim

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ndarray sub-classing and append function
by Prashant Saxena April 2, 2012

April 2, 2012

Hi, I am sub-classing numpy.ndarry for vector array representation. The append function is like this: def append(self, other): self = numpy.append(self, [other], axis=0) Example: vary = VectorArray([v1, v2]) #vary = numpy.append(vary, [v1], axis=0) vary.append(v1) The commented syntax (numpy syntax) is working but "vary.append(v1)" is not working. Any help? Cheers Prashant

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subclassing array in c
by Christoph Gohle March 30, 2012

March 30, 2012

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I have been struggeling for quite some time now. Desperate as I am, now I need help. I was trying to subclass ndarrays in a c extension (see code below) and do constantly get segfaults. I have been checking my INCREF and DECREF stuff up and down but can't find the error. Probably I got something completely wrong... anybody able to help? Thanks, Christoph - ----------------- #include <Python.h> #include <structmember.h> #include <numpy/arrayobject.h> static PyObject *SpamError; typedef struct { PyArrayObject base; PyDictObject* unit; } UnitArrayObject; PyTypeObject unitArrayObjectType; static int checkunit(PyObject *unit1, PyObject *unit2) { return PyObject_Compare(unit1, unit2); } static PyObject * unitArray_new(PyTypeObject *cls, PyObject *args, PyObject *kwargs) { PyObject *data = NULL, *unit = NULL; PyArray_Descr* dtype = NULL; PyObject *res = NULL, *tmp = NULL; if (!PyArg_ParseTuple(args, "OO|O&", &data, &unit, PyArray_DescrConverter, &dtype)) { Py_XDECREF(dtype); return NULL; } res = PyArray_FromAny(data, dtype, 0, 0, NPY_ENSURECOPY, NULL); if (res == NULL) { Py_XDECREF(dtype); //TODO: raise exception? return NULL; } if (PyObject_IsInstance(data, (PyObject*)cls)) { if (unit!=NULL && !checkunit((PyObject*)((UnitArrayObject*)data)->unit,unit)) { Py_XDECREF(res); //TODO: raise exception return NULL; } } else { if (PyObject_IsTrue(unit)) { tmp = res; res = PyArray_View((PyArrayObject*)res, NULL, &unitArrayObjectType); if (tmp!=res) { Py_XDECREF(tmp); } ((UnitArrayObject*)res)->unit = (PyDictObject*)unit; Py_INCREF(unit); if (unit!=NULL) { } } } return res; } static PyObject* unitArray__array_finalize__(PyObject* new, PyObject* args) { PyObject *attr = NULL, *tmp = NULL; PyObject *parent = NULL; if (!PyArg_ParseTuple(args, "O", &parent)) { return NULL; } if (parent!=NULL) { attr = PyObject_GetAttrString(parent, "unit"); if (attr == NULL) { //parent has no 'unit' so we make a new empty one attr = PyDict_New(); PyErr_Clear(); } } tmp = (PyObject*)((UnitArrayObject*)new)->unit; ((UnitArrayObject*)new)->unit = (PyDictObject*)attr; Py_INCREF(Py_None); return Py_None; } static PyObject* unitArray__array_wrap__(PyObject *self, PyObject *args) { PyObject *array = NULL, *context = NULL; if (!PyArg_ParseTuple(args, "OO", array, context)) { //TODO: raise exception return NULL; } printf("%s",PyString_AsString(PyObject_Str(context))); Py_INCREF(array); return array; } static PyMethodDef unitArrayMethods[] = { {"__array_finalize__", unitArray__array_finalize__, METH_VARARGS, "array finalize method"}, {"__array_wrap__", unitArray__array_wrap__, METH_VARARGS, "array wrap method"}, {NULL, NULL, 0, NULL} }; static PyMemberDef unitArrayMembers[] = { {"unit", T_OBJECT, offsetof(UnitArrayObject, unit), 0, "dictionary containing unit info."}, {NULL, 0, 0, 0, NULL} }; PyTypeObject unitArrayObjectType = { PyObject_HEAD_INIT(NULL) 0, /* ob_size */ "spam.UnitArray", /* tp_name */ sizeof(UnitArrayObject), /* tp_basicsize */ 0, /* tp_itemsize */ 0, /* tp_dealloc */ 0, /* tp_print */ 0, /* tp_getattr */ 0, /* tp_setattr */ 0, /* tp_compare */ 0, /* tp_repr */ 0, /* tp_as_number */ 0, /* tp_as_sequence */ 0, /* tp_as_mapping */ 0, /* tp_hash */ 0, /* tp_call */ 0, /* tp_str */ 0, /* tp_getattro */ 0, /* tp_setattro */ 0, /* tp_as_buffer */ Py_TPFLAGS_DEFAULT, /* tp_flags */ "A numpy array with units", /* tp_doc */ 0, /* traverseproc */ 0, /* tp_clear*/ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ unitArrayMethods, /* tp_methods */ unitArrayMembers, /* tp_members */ 0, /* tp_getset */ 0, /* tp_base*/ 0, /* tp_dict */ 0, /* tp_descr_get*/ 0, /* tp_descr_set */ 0, /* tp_dictoffset */ 0, /* tp_init */ 0, /* tp_alloc */ unitArray_new /* tp_new */ }; static PyMethodDef SpamMethods[] = { {NULL, NULL, 0, NULL} /* Sentinel */ }; PyObject *unitArray = NULL; PyMODINIT_FUNC initspampub(void) { import_array(); PyObject *m; Py_INCREF(&PyArray_Type); unitArrayObjectType.tp_base = &PyArray_Type; if (PyType_Ready(&unitArrayObjectType) < 0) return; m = Py_InitModule3("spampub", SpamMethods, "some tests and a array type with units."); if (m == NULL) return; SpamError = PyErr_NewException("spampub.error", NULL, NULL); Py_INCREF(SpamError); PyModule_AddObject(m, "error", SpamError); Py_INCREF(&unitArrayObjectType); PyModule_AddObject(m, "UnitArray", (PyObject *)&unitArrayObjectType); (void) Py_InitModule("spampub", SpamMethods); } -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.14 (Darwin) iEYEARECAAYFAk9YBbkACgkQLYu25rCEIzsExQCggHg0e0ibYP3bEsAE0Ce8Rbm3 qOcAoKwuTuE4BDZgrqNpwISgMS6uSMnO =Qtek -----END PGP SIGNATURE-----

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how to check type of array?
by Chao YUE March 29, 2012

March 29, 2012

Dear all, how can I check type of array in if condition expression? In [75]: type(a) Out[75]: <type 'numpy.ndarray'> In [76]: a.dtype Out[76]: dtype('int32') a.dtype=='int32'? thanks! Chao -- *********************************************************************************** Chao YUE Laboratoire des Sciences du Climat et de l'Environnement (LSCE-IPSL) UMR 1572 CEA-CNRS-UVSQ Batiment 712 - Pe 119 91191 GIF Sur YVETTE Cedex Tel: (33) 01 69 08 29 02; Fax:01.69.08.77.16 ************************************************************************************

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weird searchsorted behavior for unicode array
by Thouis (Ray) Jones March 29, 2012

March 29, 2012

I am seeing some very strange behavior searching a unicode array. The attached code outputs the following: UNICODE Is sorted: True Search sorted by iteration, left: [0, 1, 2, 4, 4, 6, 6, 8, 8, 10, 10, 12, 12, 13] Search sorted by iteration, right: [0, 2, 2, 4, 4, 6, 6, 8, 8, 10, 10, 12, 12, 13] Search sorted by indexing, left: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13] Search sorted by indexing, right: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13] Search sorted by indexing with copy, left: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13] Search sorted by indexing with copy, right: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13] If I remove the first print, it produces: Is sorted: True Search sorted by iteration, left: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13] Search sorted by iteration, right: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13] Search sorted by indexing, left: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13] Search sorted by indexing, right: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13] Search sorted by indexing with copy, left: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13] Search sorted by indexing with copy, right: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13] Neither answer is correct, since left and right should be offset by 1 when searching for an element in the array, by my reading of the docs. This is numpy 1.6.1 on OSX 10.6, python 2.7 Am I missing something? Thanks, Ray Jones

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Re: [Numpy-discussion] problem with dot for complex matrices
by Mark Bakker March 28, 2012

March 28, 2012

Have you tried to create your arrays with the numpy.zeros functions rather than the scipy.zeros functions? I can imagine that something may get confused here. Maybe some version mismatch or what not. Mark From: Ryan Krauss <ryanlists <at> gmail.com> Subject: Re: problem with dot for complex matrices<http://news.gmane.org/find-root.php?message_id=%3cCAAroWSa4ZgEdhb4%3dyq%5fu…> Newsgroups: gmane.comp.python.scientific.user<http://news.gmane.org/gmane.comp.python.scientific.user> Date: 2012-03-27 19:56:14 GMT (1 day and 18 minutes ago) The matrices are initially created by these lines: matout=scipy.zeros((n,n),dtype=complex128)#+0j colout=scipy.zeros((n,1),dtype=complex128)#+0j

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