Re: [Numpy-discussion] Comparison changes
On Sat, 25 Jan 2014 01:05:15 +0100, Sebastian Berg wrote: > 1. Comparison with None will broadcast in the future, so that `arr == > None` will actually compare all elements to None. (A FutureWarning for > now) This is a very useful change in behavior--thanks! Stéfan ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] Comparison changes
On Sat, 2014-01-25 at 00:18 +, Nathaniel Smith wrote: > On 25 Jan 2014 00:05, "Sebastian Berg" > wrote: > > > > Hi all, > > > > in https://github.com/numpy/numpy/pull/3514 I proposed some changes > to > > the comparison operators. This includes: > > > > 1. Comparison with None will broadcast in the future, so that `arr > == > > None` will actually compare all elements to None. (A FutureWarning > for > > now) > > > > 2. I added that == and != will give FutureWarning when an error was > > raised. In the future they should not silence these errors anymore. > (For > > example shape mismatches) > > This can just be a DeprecationWarning, because the only change is to > raise new more errors. > Right, already is the case. > > 3. We used to use PyObject_RichCompareBool for equality which > includes > > an identity check. I propose to not do that identity check since we > have > > elementwise equality (returning an object array for objects would be > > nice in some ways, but I think that is only an option for a > dedicated > > function). The reason is that for example > > > > >>> a = np.array([np.array([1, 2, 3]), 1]) > > >>> b = np.array([np.array([1, 2, 3]), 1]) > > >>> a == b > > > > will happen to work if it happens to be that `a[0] is b[0]`. This > > currently has no deprecation, since the logic is in the inner loop > and I > > am not sure if it is easy to add well there. > > Surely any environment where we can call PyObject_RichCompareBool is > an environment where we can issue a warning...? > Right, I suppose an extra identity check and comparing it with the other result is indeed no problem. So I think I will add that. - Sebastian > -n > > ___ > 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
Re: [Numpy-discussion] Comparison changes
On 25 Jan 2014 00:05, "Sebastian Berg" wrote: > > Hi all, > > in https://github.com/numpy/numpy/pull/3514 I proposed some changes to > the comparison operators. This includes: > > 1. Comparison with None will broadcast in the future, so that `arr == > None` will actually compare all elements to None. (A FutureWarning for > now) > > 2. I added that == and != will give FutureWarning when an error was > raised. In the future they should not silence these errors anymore. (For > example shape mismatches) This can just be a DeprecationWarning, because the only change is to raise new more errors. > 3. We used to use PyObject_RichCompareBool for equality which includes > an identity check. I propose to not do that identity check since we have > elementwise equality (returning an object array for objects would be > nice in some ways, but I think that is only an option for a dedicated > function). The reason is that for example > > >>> a = np.array([np.array([1, 2, 3]), 1]) > >>> b = np.array([np.array([1, 2, 3]), 1]) > >>> a == b > > will happen to work if it happens to be that `a[0] is b[0]`. This > currently has no deprecation, since the logic is in the inner loop and I > am not sure if it is easy to add well there. Surely any environment where we can call PyObject_RichCompareBool is an environment where we can issue a warning...? -n ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
[Numpy-discussion] Comparison changes
Hi all, in https://github.com/numpy/numpy/pull/3514 I proposed some changes to the comparison operators. This includes: 1. Comparison with None will broadcast in the future, so that `arr == None` will actually compare all elements to None. (A FutureWarning for now) 2. I added that == and != will give FutureWarning when an error was raised. In the future they should not silence these errors anymore. (For example shape mismatches) 3. We used to use PyObject_RichCompareBool for equality which includes an identity check. I propose to not do that identity check since we have elementwise equality (returning an object array for objects would be nice in some ways, but I think that is only an option for a dedicated function). The reason is that for example >>> a = np.array([np.array([1, 2, 3]), 1]) >>> b = np.array([np.array([1, 2, 3]), 1]) >>> a == b will happen to work if it happens to be that `a[0] is b[0]`. This currently has no deprecation, since the logic is in the inner loop and I am not sure if it is easy to add well there. Are there objections/comments to these changes? Regards, Sebastian ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
