* lights.el, compute illumination [EMACS CLIMATE ACTION INITIATIVE]
@ 2021-01-13 12:47 Emanuel Berg via Users list for the GNU Emacs text editor
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From: Emanuel Berg via Users list for the GNU Emacs text editor @ 2021-01-13 12:47 UTC (permalink / raw)
To: help-gnu-emacs
;;; -*- lexical-binding: t -*-
;;;
;;; this file:
;;; http://user.it.uu.se/~embe8573/emacs-init/lights.el
;;; https://dataswamp.org/~incal/emacs-init/lights.el
;;;
;;; data:
;;; https://dataswamp.org/~incal/data/LIGHTS
(defun illumination-score (w lm)
(interactive "nW: \nnlm: ")
(let*((le (/ lm w 1.0))
(max 75) ; LED luminous efficacy (lm/W)
(min 15) ; incandescent ditto
(scale (- max min))
(score (* 100 (/ (- le min) scale)) ))
(format "%.0f%%" score) ))
(when nil
(illumination-score
(+ (* 2 1) (* 2 2.8) 8 7) ; 22.6 W
(+ (* 2 120) 500 525) ; 1265 lm
) ; 68%
)
Turns out (as you see) that my conapt, with 4 or 6 bulbs,
scores 68%!
--
underground experts united
http://user.it.uu.se/~embe8573
https://dataswamp.org/~incal
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2021-01-13 12:47 lights.el, compute illumination [EMACS CLIMATE ACTION INITIATIVE] Emanuel Berg via Users list for the GNU Emacs text editor
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