MyVector.scala

class MyVector(val x: Double, val y: Double) {
	override def toString: String = {
		"MyVector(" + x + ", " + y + ")"
	}

	def length: Double = {
		Math.sqrt(x * x + y * y)
	}

	def direction: Double = {
		(length * length + x * x - y * y) / 2 * x * length / x
	}

	def in_parallel_with(that: MyVector) = {
		this.direction == that.direction
	}

	def unary_- : MyVector = {
		new MyVector(-x, -y)
	}

	def equals(that: MyVector): Boolean = {
		in_parallel_with(that) && this.length == that.length
	}

	def +(that: MyVector): MyVector = {
		new MyVector(x + that.x, y + that.y)
	}

	def -(that: MyVector): MyVector = {
		this + -that
	}

	def *(that: Double): MyVector = {
		new MyVector(x * that, y * that)
	}
}

object MyVector extends Application {
	val vec = new MyVector(3, 5)
	println(vec)
	println(vec.length)
	println(vec.direction)
}