Will return a nice rounded number that's easily digestible by humans. This is useful, for example, to programmatically generate an ever increasing number of bonus points, without generating numbers that looks "weird".
npm install round-to-human
# Will return a nice rounded number that's easily digestible by humans. This is
# useful, for example, to programmatically generate an ever increasing number of
# bonus points, without generating numbers that look "weird".
#
# @param n - {Number} the number we want to round
# @param options - {Object}:
# - threshold - Start rounding numbers only if they're above the threshold. By
# default, 10.
# - multiple - The multiple to use. Set to 10 by default. 5 is also recommended.
# - upwards - whether to always round upwards or not.
# - significant - number of significant digits to keep
#
module.exports = round_to_human = (n, options = {}) ->
# Set the threshold to 10 by default.
options.threshold ||= 10
# Set the multiple to 10 by default.
options.multiple ||= 10
# Set the significant digits to 2 by default
options.significant ||= 2
# Set the upward setting to true by default
options.upwards ?= true
# Round N to an integer
n = Math.round(n)
# Return the rounded number if it's lesser than or equal to the threshold
return n if n <= options.threshold
# Square 10 by the number of digits in `n` minus the significant digits
exponent = n.toString().length - options.significant - 1
len = Math.pow(10, exponent) * options.multiple
# Get the maximum between the multiple and the length, in case the digits in
# the number are lesser than or equal to the significant digits
len = Math.max(options.multiple, len)
# Round the number, plus the length, with the length as the multiple
if options.upwards and n % len
then round(n + len / 2 - 0.1, len)
else round(n, len)t = 1
for i in [0..200]
t *= 1.15
console.log "#{t}: #{round_to_human(t, multiple: 5)}"
1.15: 1
1.3224999999999998: 1
1.5208749999999995: 2
1.7490062499999994: 2
2.0113571874999994: 2
2.313060765624999: 2
2.6600198804687487: 3
3.0590228625390607: 3
3.5178762919199196: 4
4.0455577357079076: 4
4.652391396064093: 5
5.350250105473707: 5
6.152787621294762: 6
7.075705764488976: 7
8.137061629162321: 8
9.35762087353667: 9
10.761264004567169: 15
12.375453605252243: 15
14.231771646040078: 15
16.36653739294609: 20
18.821518001888002: 20
21.6447457021712: 25
24.891457557496878: 25
28.625176191121408: 30
32.918952619789614: 35
37.856795512758055: 40
43.53531483967176: 45
50.065612065622524: 50
57.5754538754659: 60
66.21177195678578: 70
76.14353775030364: 80
87.56506841284917: 90
100.69982867477654: 105
115.80480297599301: 120
133.17552342239196: 135
153.15185193575076: 155
176.12462972611337: 180
202.54332418503037: 205
232.9248228127849: 235
267.8635462347026: 270
308.043078169908: 310
354.24953989539415: 355
407.38697087970326: 410
468.4950165116587: 470
538.7692689884075: 540
619.5846593366686: 620
712.5223582371688: 715
819.400711972744: 820
942.3108187686556: 945
1083.6574415839539: 1100
1246.206057821547: 1250
1433.1369664947788: 1450
1648.1075114689954: 1650
1895.3236381893446: 1900
2179.622183917746: 2200
2506.565511505408: 2550
2882.5503382312186: 2900
3314.932888965901: 3350
3812.1728223107857: 3850
4383.998745657404: 4400
5041.598557506014: 5050
5797.8383411319155: 5800
6667.5140923017025: 6700
7667.641206146957: 7700
8817.787387069: 8850
10140.455495129348: 10500
11661.52381939875: 12000
13410.752392308561: 13500
15422.365251154844: 15500
17735.72003882807: 18000
20396.078044652277: 20500
23455.489751350116: 23500
26973.813214052632: 27000
31019.885196160525: 31500
35672.8679755846: 36000
41023.79817192229: 41500
47177.367897710625: 47500
54253.973082367214: 54500
62392.069044722295: 62500
71750.87940143063: 72000
82513.51131164523: 83000
94890.538008392: 95000
109124.1187096508: 110000
125492.7365160984: 130000
144316.64699351316: 145000
165964.1440425401: 170000
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5148188694.878639: 5150000000
5920416999.110435: 5950000000
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9004214203.52208: 9050000000
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63711170344.554695: 64000000000
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1042731251792.5127: 1050000000000
1199140939561.3894: 1200000000000
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1585863892569.9373: 1600000000000