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Re: Floating Point computations in elisp
From: |
Emanuel Berg |
Subject: |
Re: Floating Point computations in elisp |
Date: |
Sun, 20 Dec 2020 01:45:08 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) |
Jean Louis wrote:
> * Emanuel Berg via Users list for the GNU Emacs text editor
> <help-gnu-emacs@gnu.org> [2020-12-18 20:09]:
>
>> (defun compute-space-distance (dist num-beams beam-width)
>> (let*((spaces (1+ num-beams))
>> (dist-covered (* num-beams beam-width))
>> (dist-uncovered (- dist dist-covered))
>> (space (/ dist-uncovered spaces 1.0) ))
>> space ))
>>
>> ;; (insert (format "\n;; %.2f" (compute-space-distance 262 16 12)))
>> ;; 4.12
>
> If I wish to arrive to Tau Ceti from Earth and it is maybe 11.8 light
> years distant, how many years do I need to get there provided I trave
> 5,000 km per hour?
How about: 2 548 584 years
(defun tau-ceti (speed)
(let*((dist (* 11.8 9.46 (expt 10 12)))
(time (/ dist speed) )
(days (/ time 24))
(whole-days (round days)) )
(format-seconds "%y years"
(- (float-time (encode-time 0 0 0 whole-days 0 0))
(float-time (encode-time 0 0 0 0 0 0)) ))))
;; (tau-ceti 5000)
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- Floating Point computations in elisp, Christopher Dimech, 2020/12/18
- Re: Floating Point computations in elisp, Michael Heerdegen, 2020/12/18
- Re: Floating Point computations in elisp, Emanuel Berg, 2020/12/18
- Re: Floating Point computations in elisp, Jean Louis, 2020/12/18
- Re: Floating Point computations in elisp, Emanuel Berg, 2020/12/19
- Re: Floating Point computations in elisp, Emanuel Berg, 2020/12/19
- Re: Floating Point computations in elisp,
Emanuel Berg <=
- Re: Floating Point computations in elisp, Christopher Dimech, 2020/12/19
- Re: Floating Point computations in elisp, Stefan Monnier, 2020/12/19
- Re: Floating Point computations in elisp, Christopher Dimech, 2020/12/19