Rosetta Code

Angle difference between two bearings

Compute the smallest signed turn needed to move from one bearing to another.

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Sourcerosettacode/popular/angle_difference_between_two_bearings.vibe
type RunResult = {
  east_to_north: float,
  north_to_east: float,
  same_heading: float,
  wrap_clockwise: float,
  wrap_counterclockwise: float
}

def normalize(angle: float) -> float
  while angle < 0.0
    angle = angle + 360.0
  end

  while angle >= 360.0
    angle = angle - 360.0
  end

  angle
end

def angle_difference(from_bearing: float, to_bearing: float) -> float
  difference = normalize(to_bearing) - normalize(from_bearing)

  while difference <= -180.0
    difference = difference + 360.0
  end

  while difference > 180.0
    difference = difference - 360.0
  end

  difference
end

def run -> RunResult
  {
    north_to_east: angle_difference(0.0, 90.0),
    east_to_north: angle_difference(90.0, 0.0),
    wrap_clockwise: angle_difference(350.0, 10.0),
    wrap_counterclockwise: angle_difference(10.0, 350.0),
    same_heading: angle_difference(720.0, 0.0)
  }
end

Output

Click Run example to see the result.

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