Re: [Maxima-lang-fr] D'après vous, est-ce-correct comme code Maxima pour donner un exemple concernant oeis.org/A173272 ?

[Robert D. <rob...@gm...>]

Hello Patrick,

Forgive me for not replying in French, I can read it but I can't write it.
I am taking the liberty of forwarding your message to the primary Maxima
mailing list, maxima-discuss. I think there are readers there who can reply
in French.

About the method for determining the root of the equation in Maxima, I
believe that your method is valid, and I can't suggest a better approach.

I'm glad to hear Maxima is getting a mention in the OEIS. It is a terrific
resource which I have used many times.

All the best,

Robert Dodier


On Sat, Nov 12, 2022 at 9:28 AM Patrick GUILLEMIN <
pat...@ho...> wrote:

> Bonjour,
>
> Je vais soumette l’exemple de code MAXIMA suivant à
> https://oeis.org/A173272 ; Est-ce correct (*) pour vous?
>
> Le record donné par G. C. Greubel est de 10 000 digits.
>
> J’en donne 150 parce que MAPLE en donne 120 (comme Mathematica)
>
>
>
> /* OEIS A173272 Decimal expansion of the positive solution of
> sqrt((2-x)(2+x)) + sqrt((3-x)(a+x)) = sqrt((2-x)(2+x))*sqrt((3-x)(3+x)). */
>
> /* After MAPLE and MATHEMATICA examples, Patrick Guillemin is adding a
> MAXIMA example with 150 Digits */
>
> find_root_abs:1/10^150$ find_root_rel:1/10^150$ fpprec:150$
> fpprintprec:150$
>
> x0:bf_find_root(x^8-22*x^6+163*x^4-454*x^2+385, x, 1.1b0, 1.3b0);
>
> /* end of code */
>
>
>
> Afin de donner le change à MAPLE et MATHEMATICA
>
>
>
> EXAMPLE
>
> 1.231185723778668829962705... [R. J. Mathar, Feb 21 2010]
>
>
>
> MAPLE
>
> Digits := 120 ; fsolve(x^8-22*x^6+163*x^4-454*x^2+385, x, 1.1..1.3) ; # R.
> J. Mathar, Feb 21 2010
>
> MATHEMATICA
>
> Root[#^8 - 22#^6 + 163#^4 - 454#^2 + 385 &, 3] // RealDigits[#, 10, 105]&
> // First (* Jean-François Alcover, Feb 22 2013 *)
>
> RealDigits[x/.FullSimplify[With[{a=Sqrt[(2-x)(2+x)], b=Sqrt[(3-x)(3+x)]},
> Solve[a*b==a+b, x]]][[2]], 10, 120][[1]] (* Essentially identical to Jean-
> Francois Alcover's program above *) (* Harvey P. Dale, Dec 26 2014 *)
>
> Cordialement
>
> Patrick
>
>
>
> PS
>
> (*) J’ai vérifié les 150 digits, ils sont corrects mais je me demande si
> j’ai utilisé la bonne façon de faire avec MAXIMA ?
>
>
>
> /* x0 result OK until a(150) comparing x first 150 digits with OEIS
> A173272 / a(1) to a(157) of G. C. Greubel, Table of n, a(n) for n =
> 1..10000 Reference */
>
> /*
> 1.23118572377866882996270583476978887456864902699763492434384690286327883546368258020702207613654231577873867592541119320307117751737256969245684339511b0
> x0 150 digits*/
>
> /*
> 1.231185723778668829962705834769788874568649026997634924343846902863278835463682580207022076136542315778738675925411193203071177517372569692456843395112022705
> OEIS reference 157 digits */
>
>
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