[sage-support] Re: limitations of "solve"?

These systems and Sage’s “solutions” exhibit some *serious* problems. See there … ​ Le mardi 2 janvier 2024 à 12:30:14 UTC+1, Emmanuel Charpentier a écrit : > FWIW, a working workaround this interesting Maxima quirk (bug ?) is to use >

[sage-support] Re: limitations of "solve"?

These systems and Sage's "solutions" exhibit some *serious* problems. See [there](https://groups.google.com/g/sage-support/c/gGssS_15jxE)... Le mardi 2 janvier 2024 à 12:30:14 UTC+1, Emmanuel Charpentier a écrit : > FWIW, a working workaround this interesting Maxima quirk (bug ?) is to use >

[sage-support] Re: limitations of "solve"?

FWIW, a working workaround this interesting Maxima quirk (bug ?) is to use sympy, as demonstrated here

Re: [sage-support] Re: limitations of "solve"?

I did go on to discuss this on the Maxima mailing list: https://sourceforge.net/p/maxima/mailman/maxima-discuss/thread/CADB8Zm56axVDFXRLbJnxm7xnnbQiixBzg4VX1T91ucj%2B-tuGvA%40mail.gmail.com/#msg58347791 Apparently domain:complex as used by Sage is not a very well tested configuration of Maxima.

Re: [sage-support] Re: limitations of "solve"?

The documented effect is usually of most impact: https://maxima.sourceforge.io/docs/manual/maxima_46.html#index-domain there may be other undocumented effects, but the one above tends to explain a lot already. On Sunday 3 December 2023 at 06:26:20 UTC-8 Oscar Benjamin wrote: > What does "set

Re: [sage-support] Re: limitations of "solve"?

What does "set domain to complex" mean in terms of Maxima's settings? Maxima's solve seems to compute complex solutions by default: (%i21) solve(x^2 + 1); (%o21)[x = - %i, x = %i] On Sun, 3 Dec 2023 at 13:37, Dima Pasechnik wrote: > > Yes, Sage modifies the defaults of

Re: [sage-support] Re: limitations of "solve"?

Oh, I see: (%i23) domain: complex ; (%o23) complex (%i24) f: 10*x^(1/3)*y^(2/3)$ (%i25) g: 5*x^2 + 6*y$ (%i26) solve([diff(f,x)=l*diff(g,x), diff(f,y)=l*diff(g,y), g=120], [x,y,l]); (%o26)[] On Sun, 3 Dec 2023 at 14:20, Oscar

Re: [sage-support] Re: limitations of "solve"?

Is there a way to change the default when calling "solve"? Fernando On 12/3/2023 8:37 AM, Dima Pasechnik wrote: Yes, Sage modifies the defaults of Maxima, in particular we set domain to complex. On 3 December 2023 12:28:45 GMT, Oscar Benjamin wrote: On Wed, 29 Nov 2023 at 12:40, Eric

Re: [sage-support] Re: limitations of "solve"?

Yes, Sage modifies the defaults of Maxima, in particular we set domain to complex. On 3 December 2023 12:28:45 GMT, Oscar Benjamin wrote: >On Wed, 29 Nov 2023 at 12:40, Eric Gourgoulhon wrote: >> >> Le mardi 28 novembre 2023 à 18:25:04 UTC+1, kcrisman a écrit : >> >> Yes. Maxima's attitude

Re: [sage-support] Re: limitations of "solve"?

On Wed, 29 Nov 2023 at 12:40, Eric Gourgoulhon wrote: > > Le mardi 28 novembre 2023 à 18:25:04 UTC+1, kcrisman a écrit : > > Yes. Maxima's attitude is that the square root of negative one is an > expression which might have multiple values, rather than just picking one you > hope might be

Re: [sage-support] Re: limitations of "solve"?

I wouldn't mind seeing those discussions if you have a link to send (perhaps only to me). A relatively recent one (mentioning Eric's workaround) is https://groups.google.com/g/sage-devel/c/h50LZVLVQI4/m/AieyOKHVAQAJ (Note that there were at times separate problems with the

[sage-support] Re: limitations of "solve"?

Hi, Le mardi 28 novembre 2023 à 18:25:04 UTC+1, kcrisman a écrit : Yes. Maxima's attitude is that the square root of negative one is an expression which might have multiple values, rather than just picking one you hope might be consistent over branch points. To enforce Maxima to work in

Re: [sage-support] Re: limitations of "solve"?

On Tue, 28 Nov 2023 at 17:25, kcrisman wrote: > > Answering part of my question: it seems that sympy and maxima have > different attitudes towards fractional powers of negative numbers, which > may be the source of the problem. > > Yes. Maxima's attitude is that the square root of negative one

[sage-support] Re: limitations of "solve"?

Answering part of my question: it seems that sympy and maxima have different attitudes towards fractional powers of negative numbers, which may be the source of the problem. Yes. Maxima's attitude is that the square root of negative one is an expression which might have multiple values,

Re: [sage-support] Re: limitations of "solve"?

one should not be using sagecell.sagemath.org server for teaching, it's not scaling well (compared to cocalc.com, say) under load. unleashing undergraduates to compute on it surely gets things very slow there On 28 November 2023 15:45:33 GMT, Eric Gourgoulhon wrote: >Hi, > >I've also

[sage-support] Re: limitations of "solve"?

Answering part of my question: it seems that sympy and maxima have different attitudes towards fractional powers of negative numbers, which may be the source of the problem. If I change to g(x,y)=x^2+6*y then "solve" has no problem finding x=2*sqrt(6), y=16. Fernando On 11/28/2023 10:36

[sage-support] Re: limitations of "solve"?

Hi, I've also noticed two days ago that https://sagecell.sagemath.org/ is very slow (actually does not terminate) even on elementary operations. Maybe there is a problem with the server at the moment... Eric. Le mardi 28 novembre 2023 à 16:36:30 UTC+1, Fernando Q. Gouvea a écrit : >