On Tue, Oct 30, 2018 at 12:49 AM Eric Wieser <wieser.eric+nu...@gmail.com> wrote:
> The latter - changing the behavior of multiplication breaks the principle. > > But this is not the main reason for deprecating matrix - almost all of the > problems I’ve seen have been caused by the way that matrices behave when > sliced. The way that m[i][j] and m[i,j] are different is just one example > of this, the fact that they must be 2d is another. > > Matrices behaving differently on multiplication isn’t super different in > my mind to how string arrays fail to multiply at all. > The difference is that string arrays are not numeric. This is an issue since people want to pass a matrix Into places that want to multiple element wise but that then breaks that code unless special provisions are taken. Numerical codes don’t work on string arrays anyway. Eric Eric > > On Mon, 29 Oct 2018 at 20:54 Ralf Gommers <ralf.gomm...@gmail.com> wrote: > > On Mon, Oct 29, 2018 at 4:31 PM Chris Barker <chris.bar...@noaa.gov> >> wrote: >> >>> On Fri, Oct 26, 2018 at 7:12 PM, Travis Oliphant <teoliph...@gmail.com> >>> wrote: >>> >>> >>>> agree that we can stop bashing subclasses in general. The problem >>>> with numpy subclasses is that they were made without adherence to SOLID: >>>> https://en.wikipedia.org/wiki/SOLID. In particular the Liskov >>>> substitution principle: >>>> https://en.wikipedia.org/wiki/Liskov_substitution_principle . >>>> >>> >>> ... >>> >>> >>>> did not properly apply them in creating np.matrix which clearly >>>> violates the substitution principle. >>>> >>> >>> So -- could a matrix subclass be made "properly"? or is that an example >>> of something that should not have been a subclass? >>> >> >> The latter - changing the behavior of multiplication breaks the principle. >> >> Ralf >> >> _______________________________________________ >> NumPy-Discussion mailing list >> NumPy-Discussion@python.org >> https://mail.python.org/mailman/listinfo/numpy-discussion >> > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@python.org > https://mail.python.org/mailman/listinfo/numpy-discussion >
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