Swift (iOS/macOS): 画像を画面に表示

Simulator Screen Shot 2016.07.17 19.02.57

    func showImage() {
        let image = UIImage(named: "image.jpg")
        let imageView = UIImageView(image: image)
        imageView.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.width*3/4)
        
        self.view.addSubview(imageView)
    }