On Sun, Mar 8, 2009 at 4:54 PM, Charles R Harris <charlesr.har...@gmail.com>wrote:
> > > On Sun, Mar 8, 2009 at 2:48 PM, Charles R Harris < > charlesr.har...@gmail.com> wrote: > >> >> >> On Sun, Mar 8, 2009 at 1:04 PM, Darren Dale <dsdal...@gmail.com> wrote: >> >>> On Sat, Mar 7, 2009 at 1:23 PM, Darren Dale <dsdal...@gmail.com> wrote: >>> >>>> On Sun, Feb 22, 2009 at 7:01 PM, Darren Dale <dsdal...@gmail.com>wrote: >>>> >>>>> On Sun, Feb 22, 2009 at 6:35 PM, Darren Dale <dsdal...@gmail.com>wrote: >>>>> >>>>>> On Sun, Feb 22, 2009 at 6:28 PM, Pierre GM <pgmdevl...@gmail.com>wrote: >>>>>> >>>>>>> >>>>>>> On Feb 22, 2009, at 6:21 PM, Eric Firing wrote: >>>>>>> >>>>>>> > Darren Dale wrote: >>>>>>> >> Does anyone know why __array_wrap__ is not called for subclasses >>>>>>> >> during >>>>>>> >> arithmetic operations where an iterable like a list or tuple >>>>>>> >> appears to >>>>>>> >> the right of the subclass? When I do "mine*[1,2,3]", array_wrap is >>>>>>> >> not >>>>>>> >> called and I get an ndarray instead of a MyArray. "[1,2,3]*mine" >>>>>>> is >>>>>>> >> fine, as is "mine*array([1,2,3])". I see the same issue with >>>>>>> >> division, >>>>>>> > >>>>>>> > The masked array subclass does not show this behavior: >>>>>>> >>>>>>> Because MaskedArray.__mul__ and others are redefined. >>>>>>> >>>>>>> Darren, you can fix your problem by redefining MyArray.__mul__ as: >>>>>>> >>>>>>> def __mul__(self, other): >>>>>>> return np.ndarray.__mul__(self, np.asanyarray(other)) >>>>>>> >>>>>>> forcing the second term to be a ndarray (or a subclass of). You can >>>>>>> do >>>>>>> the same thing for the other functions (__add__, __radd__, ...) >>>>>> >>>>>> >>>>>> Thanks for the suggestion. I know this can be done, but ufuncs like >>>>>> np.multiply(mine,[1,2,3]) will still not work. Plus, if I reimplement >>>>>> these >>>>>> methods, I take some small performance hit. I've been putting a lot of >>>>>> work >>>>>> in lately to get quantities to work with numpy's stock ufuncs. >>>>>> >>>>> >>>>> I should point out: >>>>> >>>>> import numpy as np >>>>> >>>>> a=np.array([1,2,3,4]) >>>>> b=np.ma.masked_where(a>2,a) >>>>> np.multiply([1,2,3,4],b) # yields a masked array >>>>> np.multiply(b,[1,2,3,4]) # yields an ndarray >>>>> >>>>> >>>> I'm not familiar with the numpy codebase, could anyone help me figure >>>> out where I should look to try to fix this bug? I've got a nice set of >>>> generators that work with nosetools to test all combinations of numerical >>>> dtypes, including combinations of scalars, arrays, and iterables of each >>>> type. In my quantities package, just testing multiplication yields 1031 >>>> failures, all of which appear to be caused by this bug (#1026 on trak) or >>>> bug #826. >>> >>> >>> >>> I finally managed to track done the source of this problem. >>> _find_array_wrap steps through the inputs, asking each of them for their >>> __array_wrap__ and binding it to wrap. If more than one input defines >>> __array_wrap__, you enter a block that selects one based on array priority, >>> and binds it back to wrap. The problem was when the first input defines >>> array_wrap but the second one does not. In that case, _find_array_wrap never >>> bothered to rebind the desired wraps[0] to wrap, so wrap remains Null or >>> None, and wrap is what is returned to the calling function. >>> >>> I've tested numpy with this patch applied, and didn't see any >>> regressions. Would someone please consider committing it? >>> >>> Thanks, >>> Darren >>> >>> $ svn diff numpy/core/src/umath_ufunc_object.inc >>> Index: numpy/core/src/umath_ufunc_object.inc >>> =================================================================== >>> --- numpy/core/src/umath_ufunc_object.inc (revision 6569) >>> +++ numpy/core/src/umath_ufunc_object.inc (working copy) >>> @@ -3173,8 +3173,10 @@ >>> PyErr_Clear(); >>> } >>> } >>> + if (np >= 1) { >>> + wrap = wraps[0]; >>> + } >>> if (np >= 2) { >>> - wrap = wraps[0]; >>> maxpriority = PyArray_GetPriority(with_wrap[0], >>> PyArray_SUBTYPE_PRIORITY); >>> for (i = 1; i < np; ++i) { >>> >> >> Applied in r6573. Thanks. >> > > Oh, and can you provide a test for this fix? > Yes, I'll send a patch for a test as soon as its ready. 6573 closes two tickets, 1026 and 1022. Did you see the patch I sent for issue #826? It is also posted at the bug report. Darren
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