Nuumeric#round_to_nearest

round_to_nearest.rb

class Numeric
  def round_to_nearest(delta = 0.25)
    return self if delta.to_f == 0.0
    ((to_f / delta.to_f).round * delta.to_f)
  end

  def floor_to_nearest(delta = 0.25)
    return self if delta.to_f == 0.0
    ((to_f / delta.to_f).floor * delta.to_f)
  end

  def ceil_to_nearest(delta = 0.25)
    return self if delta.to_f == 0.0
    ((to_f / delta.to_f).ceil * delta.to_f)
  end
end