class Object

Public Instance Methods

ncr(n, r) click to toggle source
# File lib/probaberry/counting.rb, line 22
def ncr n, r
  raise ArgumentError, "r = #{r} is outside 0..#{n}" if r < 0 or r > n
  n.choose r
end
nice(n, p=3) click to toggle source
# File lib/probaberry/nice.rb, line 1
def nice n, p=3
  return n unless n.kind_of? Numeric
  i = n.to_i
  f = ((n - i).round(p).to_s)[2..-1]
  i = i.to_s.reverse.gsub(/...(?=.)/, '\& ').reverse
  "#{i}.#{f}"
end
npr(n, r) click to toggle source
# File lib/probaberry/counting.rb, line 27
def npr n, r
  raise ArgumentError, "r = #{r} is outside 0..#{n}" if r < 0 or r > n
  n.!.fdiv((n - r).!).to_i
end