Re: [Numpy-discussion] Deprecate poly1d and replace with Poly1d ?
On Mon, Sep 28, 2009 at 2:59 PM, Robert Kern wrote: > On Mon, Sep 28, 2009 at 15:46, Charles R Harris > wrote: > > > The more basic problem here is making poly1d look like an array, which it > > isn't. The array bit is an implementation detail and would be private in > > C++. with an as_array method to retrieve the details if wanted. > > I'm pretty sure that it is an intentional public API and not an > implementation detail. The __array__() method is not "making poly1d > look like an array"; it is the standard name for such as_array() > conversion methods. > > Exactly, and that is why it is a design decision error. It *shouldn't* work with as_array unless it is *an array*, which it isn't. Really In [19]: sin(poly1d([1,2,3])) Out[19]: array([ 0.84147098, 0.90929743, 0.14112001]) That makes no sense. On the other hand, it is difficult to make arrays of poly1d, which does make sense because the polynomials are a commutative ring. Chuck ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] Deprecate poly1d and replace with Poly1d ?
On Mon, Sep 28, 2009 at 15:46, Charles R Harris wrote: > The more basic problem here is making poly1d look like an array, which it > isn't. The array bit is an implementation detail and would be private in > C++. with an as_array method to retrieve the details if wanted. I'm pretty sure that it is an intentional public API and not an implementation detail. The __array__() method is not "making poly1d look like an array"; it is the standard name for such as_array() conversion methods. -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
[Numpy-discussion] Deprecate poly1d and replace with Poly1d ?
Because poly1d exports the __array__ interface, a design error IMHO that makes it play badly with the prospective chebyshev module. For example the following should convert from a Chebyshev series to a power series chebval([1,0,0], poly1d(1,0)) and it does if I make sure to pass the poly1d as object in an array, but to do that I have to check that it is an instance of poly1d and take special measures. I shouldn't have to do that, it violates duck typing. The more basic problem here is making poly1d look like an array, which it isn't. The array bit is an implementation detail and would be private in C++. with an as_array method to retrieve the details if wanted. Chuck ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
