Re: [sage-devel] Re: Synchronization of GitHub state and priority labels continues on Tuesday July 11th

2024-08-28 Thread Kwankyu Lee
Another instance of annoyance: https://github.com/sagemath/sage/pull/38564 I am fighting with the dumb synchronizer. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email

[sage-devel] Adjusting tabs of EXAMPLES

2024-08-28 Thread Kwankyu Lee
Hi, In PR https://github.com/sagemath/sage/pull/38568, we are adjusting the style of the tabbed EXAMPLES, recently introduced. You may come by and participate. First, look through all screenshots in the PR. Second, understand the candidates in https://github.com/sagemath/sage/pull/38568#issue

Re: [sage-devel] QQbar(-1)^(1/3) != AA(-1)^(1/3)

2024-08-28 Thread Dima Pasechnik
This looks like RR should be fixed to match AA here. On 28 August 2024 12:40:49 BST, Kwankyu Lee wrote: >sage: ZZ(-1).nth_root(3) >-1 >sage: _.parent() >Integer Ring >sage: QQ(-1).nth_root(3) >-1 >sage: _.parent() >Rational Field >sage: RR(-1).nth_root(3) >-1.00 >sage: _.parent() >Rea

Re: [sage-devel] QQbar(-1)^(1/3) != AA(-1)^(1/3)

2024-08-28 Thread Dima Pasechnik
On 28 August 2024 12:28:54 BST, Kwankyu Lee wrote: > > >On Wednesday, August 28, 2024 at 7:57:43 PM UTC+9 john.c...@gmail.com wrote: > >Surely the output of -1 for AA(-1)^(1/3) is correct: AA is the "Algebraic >Real Field" and -1 has exactly one cube root in there, namely itself. On >the ot

Re: [sage-devel] QQbar(-1)^(1/3) != AA(-1)^(1/3)

2024-08-28 Thread Georgi Guninski
All of the following return the complex branch: pari/gp, mpmath, maxima -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To

Re: [sage-devel] QQbar(-1)^(1/3) != AA(-1)^(1/3)

2024-08-28 Thread Kwankyu Lee
[forwarded from Dima] This looks like RR should be fixed to match AA here. On 28 August 2024 12:40:49 BST, Kwankyu Lee wrote: sage: ZZ(-1).nth_root(3) -1 sage: _.parent() Integer Ring sage: QQ(-1).nth_root(3) -1 sage: _.parent() Rational Field sage: RR(-1).nth_root(3) -1.00 sage: _.

Re: [sage-devel] QQbar(-1)^(1/3) != AA(-1)^(1/3)

2024-08-28 Thread Kwankyu Lee
[fowarded from Dima] > >x^(1/n) and x.nth_root(n) do not behave in the same way. All x.nth_root(n) >gives an n-th root in the same field to which x belongs while all x^(1/n) >gives the primitive n-th root of unity, with the exception of AA(-1)^(1/n). the function 1/n : AA->AA is 1-1 on all AA, a

Re: [sage-devel] QQbar(-1)^(1/3) != AA(-1)^(1/3)

2024-08-28 Thread Kwankyu Lee
sage: ZZ(-1).nth_root(3) -1 sage: _.parent() Integer Ring sage: QQ(-1).nth_root(3) -1 sage: _.parent() Rational Field sage: RR(-1).nth_root(3) -1.00 sage: _.parent() Real Field with 53 bits of precision sage: CC(-1).nth_root(3) 0.500 + 0.866025403784439*I sage: _.parent() Co

Re: [sage-devel] QQbar(-1)^(1/3) != AA(-1)^(1/3)

2024-08-28 Thread Kwankyu Lee
On Wednesday, August 28, 2024 at 7:57:43 PM UTC+9 john.c...@gmail.com wrote: Surely the output of -1 for AA(-1)^(1/3) is correct: AA is the "Algebraic Real Field" and -1 has exactly one cube root in there, namely itself. On the other hand, QQbar(-1) has 3 cube roots and one is chosen (in som

Re: [sage-devel] QQbar(-1)^(1/3) != AA(-1)^(1/3)

2024-08-28 Thread Kwankyu Lee
It is puzzling, but it does not seem to be so. If 1/3 would be a python float, (-1)**(1/3) is not defined under the usual definition of x^y = exp(y*ln(x)) with the standard branch cut for the logarithmic function. If Python includes the negative axis in the domain of ln(x), and defines ln(

Re: [sage-devel] QQbar(-1)^(1/3) != AA(-1)^(1/3)

2024-08-28 Thread John Cremona
Surely the output of -1 for AA(-1)^(1/3) is correct: AA is the "Algebraic Real Field" and -1 has exactly one cube root in there, namely itself. On the other hand, QQbar(-1) has 3 cube roots and one is chosen (in some deterministic way). I do not think that AA(-1)^(1/3) should return a cubroot

Re: [sage-devel] QQbar(-1)^(1/3) != AA(-1)^(1/3)

2024-08-28 Thread Kwankyu Lee
> >>> (-1)**(1/3) > (0.5001+0.8660254037844386j) Your example illustrates twice that an operation can lead to a bigger set : 1/3 is a python float :-) It is puzzling, but it does not seem to be so. If 1/3 would be a python float, (-1)**(1/3) is not defined under the usual defi