module ClockAngleCalculator

Constants

VERSION

Public Class Methods

calculate_angle(hour, minute) click to toggle source

given an hour and minute, model the time on an analog clock return the angle between the hour and minute hands on the clock

# File lib/clock_angle_calculator.rb, line 19
def self.calculate_angle(hour, minute)
  return calculate_angle_helper(hour, minute)
end

calculate_angle_datetime(datetime) click to toggle source

given a datetime, model the time on an analog clock return the angle between the hour and minute hands on the clock

# File lib/clock_angle_calculator.rb, line 7
def self.calculate_angle_datetime(datetime)
  if datetime.is_a?(DateTime) || datetime.is_a?(Time) || datetime.is_a?(Date)
    hour = (datetime.strftime("%H")).to_f % 12
    minute = datetime.strftime("%M").to_f
    return calculate_angle_helper(hour, minute)
  else
    return nil
  end
end

Private Class Methods

calculate_angle_helper(hour, minute) click to toggle source

private helper method used to determine the angle

# File lib/clock_angle_calculator.rb, line 24
def self.calculate_angle_helper(hour, minute)
  if hour < 0 || hour > 12 || minute < 0 || minute > 59
    return nil
  end
  hourly_degree = (360.0 / 12.0)
  minute_degree = (360.0 / 60.0)

  minute_angle = (minute_degree * (minute % 60)).to_f
  hour_angle = ((hourly_degree * (hour % 12)) + ((minute / 60.0) * hourly_degree)).to_f

  angle = (hour_angle - minute_angle).abs
  if angle > 180
    angle = 360 - angle
  end

  return angle
end