On Wed, Sep 22, 2010 at 1:31 PM, Sebastian Walter < sebastian.wal...@gmail.com> wrote:
> Hello Friedrich, > > I have read your proposal. You describe issues that I have also > encountered several times. > I believe that your priops approach would be an improvement over the > current overloading of binary operators. > That being said, I think the issue is not so much numpy but rather the > way Python implements operator overloading using methods like __add__ > and __radd__. Hence, your suggestion seems to be a Python Enhancement > Proposal and should be discussed without any references to numpy or > bugs related to numpy.set_numeric_ops. > Maybe you could also have a look at Go's interfaces (Googles > programming language) which seems to be somewhat related to your > approach. Also, have you checked the Python mail archive? Issues like > that tend to be discussed from time to time. > > On a more practical note: Why exactly do you use set_numeric_ops? You > could also > 1) use numpy.ndarrays with dtype=object > 2) or create new numpy.ndarray -like class and set __array_priority__ > 2 > both approaches work well for me. > > just my 2 cents, > Sebastian > > > > On Thu, Sep 16, 2010 at 2:02 PM, Friedrich Romstedt > <friedrichromst...@gmail.com> wrote: > > I just ran across the problem of priorities with ndarrays again and it > > keeps biting me. I did once ago a workaround to get my ``undarray`` > > class's methods be called when being the second operand of e.g. > > <ndarray> + <undarray>. But since I wrote it, always Python crashes > > on exit with the message: > > > > Python-32(68665) malloc: *** error for object 0x239680: incorrect > > checksum for freed object - object was probably modified after being > > freed. > > *** set a breakpoint in malloc_error_break to debug > > > > (Of course only if I imported the module. Occasionally I also > > observed Bus errors, and even segfaults.) > > I overloaded the numpy ops via numpy.set_numeric_ops() with > > self-written classes, which are *not* derived from numpy.ufunc, and do > > not resemble numpy ufuncs completely. > > > > So I want to do it properly this time. > > > > I therefore started with writing a Letter of Intent, and put it online > > on http://github.com/friedrichromstedt/priops . > > > > Opinions? > > > > Friedrich > > > > P.S.: I will start coding anyway, but it would be nice. > > > > P.P.S.: The package this originates from is also online, under > > http://github.com/friedrichromstedt/upy, or > > http://upy.sourceforge.net. I will probably create a small example > > script demonstrating the crash. > > _______________________________________________ > > NumPy-Discussion mailing list > > NumPy-Discussion@scipy.org > > http://mail.scipy.org/mailman/listinfo/numpy-discussion > > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion >
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