Class: Integer

Inherits:
Object
  • Object
show all
Defined in:
lib/ndr_support/integer/working_days.rb,
lib/ndr_support/integer/rounding.rb,
lib/ndr_support/integer/calculations.rb

Overview

Mixin for working_days

Instance Method Summary collapse

Instance Method Details

#choose(k) ⇒ Object

Gets binomial coefficients:

4.choose(2) #=> 6



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# File 'lib/ndr_support/integer/calculations.rb', line 6

def choose(k)
  fail(ArgumentError, "cannot choose #{k} from #{self}") unless (0..self) === k
  self.factorial / (k.factorial * (self - k).factorial)
end

#factorial ⇒ Object 



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# File 'lib/ndr_support/integer/calculations.rb', line 11

def factorial
  fail("cannot calculate #{self}.factorial") unless self >= 0 # limited implementation
  self.zero? ? 1 : (1..self).inject { |product, i| product * i }
end

#round_up_to(p) ⇒ Object

Rounds up to p digits. For graphs. Josh Pencheon 22/08/2007



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# File 'lib/ndr_support/integer/rounding.rb', line 3

def round_up_to(p)
  return nil if p > self.to_s.length || p < 0
  p = p.to_i
  s = self.to_s.split('')
  d = s[0..(p - 1)]
  d[p - 1] = s[p - 1].to_i + 1
  s[p..-1].each_with_index { |_v, i| d[i + p] = '0' }
  d.join.to_i
end

#working_days_since(date) ⇒ Object

Returns a date of the number of working days since a given date



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# File 'lib/ndr_support/integer/working_days.rb', line 4

def working_days_since(date)
  times do
    date = date.next
    date = date.next while date.public_holiday? || !date.weekday?
  end
  date
end