   }
 
   func testRotateDegrees() {
-    let v1 = vec2(2, 3);
+    let v1 = vec2(2.0, 3.0);
     let v2 = v1.rotate(degrees: 90)
     XCTAssertEqualWithAccuracy(v2.angleDegrees, v1.angleDegrees + 90.0, accuracy: epsilon)
     let v3 = v1.rotate(degrees: 180)

  }

  func testNormalize() {
    let v1 = vec2(100, 1000)
    let v2 = v1.normalize()
    XCTAssertEqualWithAccuracy(v2.length, 1.0, accuracy: epsilon)
    XCTAssertEqualWithAccuracy(v1.angle, v2.angle, accuracy: epsilon)
  }

  func testNormalizeZero() {
    let v1 = vec2(0, 0)
    let v2 = v1.normalize()
    XCTAssertEqualWithAccuracy(v2.length, 0.0, accuracy: epsilon)
    XCTAssertEqualWithAccuracy(v1.angle, v2.angle, accuracy: epsilon)

    let p2 = CGPoint(x: 3, y: 4)

    let v1 = vec2(from:p1, to:p2)
    let v2 = vec2(2.0, 3.0)

    XCTAssertEqual(v1, v2)
  }
