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Re: Calculator: no exponent, full number ?
From: |
tomas |
Subject: |
Re: Calculator: no exponent, full number ? |
Date: |
Thu, 6 Jun 2019 19:04:59 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Thu, Jun 06, 2019 at 06:50:55PM +0200, Emanuel Berg via help-gnu-emacs wrote:
> Marcin Borkowski wrote:
>
> >> (defun hypotenuse (c1 c2)
> >> (sqrt (+ (* c1 c1) (* c2 c2))) )
> >
> > Just for the fun, let me mention that this is
> > not a very good algorithm for computing the
> > Pythagorean sum - it may happen that both the
> > operands and the result lie within the bounds
> > for the given type but this calculation blows
> > up because of large squares overflowing.
>
> Well, first let it be known that Marcin is
> a professional mathematician, famous for his
> remarkable calculations. That said, the above
> comment is on the computer side of things,
> right? In the math world, what would happen is
> just a very large triangle, again - right?
>
> Assuming integers, how large can they be in
> Emacs Lisp? Eval us:
>
> most-positive-fixnum ; 536870911
> "Typical values are 2**29 − 1 on 32-bit and
> 2**61 − 1 on 64-bit platforms." [1]
[...]
Newer Emacsen support bignums:
(expt 71 71) =>
275006373483461607657434076627252658495183350017755660813753981774508905998081919405140568848353397233796618192645698819765129996471
That said, calc itself supports bignums since
long.
Cheers
-- t
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- Re: Calculator: no exponent, full number ?, (continued)
- Re: Calculator: no exponent, full number ?, Emanuel Berg, 2019/06/04
- Re: Calculator: no exponent, full number ?, Marcin Borkowski, 2019/06/05
- Re: Calculator: no exponent, full number ?, Emanuel Berg, 2019/06/05
- Re: Calculator: no exponent, full number ?, jonetsu, 2019/06/05
- Re: Calculator: no exponent, full number ?, Marcin Borkowski, 2019/06/06
- Re: Calculator: no exponent, full number ?, Emanuel Berg, 2019/06/06
- Re: Calculator: no exponent, full number ?,
tomas <=
- Re: Calculator: no exponent, full number ?, Emanuel Berg, 2019/06/06
- Re: Calculator: no exponent, full number ?, tomas, 2019/06/06
- Re: Calculator: no exponent, full number ?, Marcin Borkowski, 2019/06/07
Re: Calculator: no exponent, full number ?, Van L, 2019/06/14
Re: Calculator: no exponent, full number ?, Emanuel Berg, 2019/06/14
Re: Calculator: no exponent, full number ?, Van L, 2019/06/15
Re: Calculator: no exponent, full number ?, Joe_Trivers, 2019/06/06