class Array

# File lib/fnordmetric/ext.rb, line 60
def emtpy
  self.size == 0
end

# File lib/fnordmetric/ext.rb, line 37
def mean
  return 0 if empty?
  inject(&:+).to_f / size
end

# File lib/fnordmetric/ext.rb, line 44
def median
  return 0 if empty?
  (_sorted = self.dup.sort)[_sorted.size/2]
end

# File lib/fnordmetric/ext.rb, line 54
def mode
  return 0 if empty?
  inject({}){ |h,v| h[v] = h[v].to_i+1; h }.to_a
  .sort{ |a,b| b.last <=> a.last }[0][0]
end

# File lib/fnordmetric/ext.rb, line 49
def range
  return 0 if empty?
  max - min
end