Re: Floating Point computations in elisp

[Emanuel Berg]

Jean Louis wrote:

> 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?

I don't know, 215 981 years?

(defun tau-ceti (speed)
  (let*((dist  (* 9.46 (expt 10 12)))
        (time  (/ dist speed) )
        (hours (round time)) )
    (format-seconds "%y years"
                    (- (float-time (encode-time 0 0 hours 0 0 0))
                       (float-time (encode-time 0 0     0 0 0 0)) ))))
;; (tau-ceti 5000)

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