Class: Numeric

Inherits:
Object
  • Object
show all
Defined in:
lib/sixarm_ruby_numeric_percent.rb

Overview

Please see README

Instance Method Summary collapse

Instance Method Details

#percent(precision = nil) ⇒ Object

Calculate a number as percentage with rounding:

x=0.1234
x.percent => 12

Optional precision:

x.percent(nil) => 12 (default is to round to an integer)
x.percent(1) => 10
x.percent(2) => 12
x.percent(3) => 12.3
x.percent(4) => 12.34

Special cases:

NaN.percent => NaN
Infinite.percent => Infinite

Note that precision 1 and 2 are optimized for speed and also to return integers; other precisions return floats.



30
31
32
33
34
35
36
37
38
39
40
41
 
# File 'lib/sixarm_ruby_numeric_percent.rb', line 30

def percent(precision=nil)
  return self if (respond_to?('nan?') && nan?) || (respond_to?('infinite?') && infinite?) 
  # Optimized for speed for the most common cases
  return case precision
  when nil, 2
    (self * 100).round 
  when 1
    (self * 10).round * 10
  else
    (self * (10 ** precision)).round.to_f / (10 ** (precision - 2)).to_f
  end
end