【Xcode/Swift】流れるアニメーションを表示する

import UIKit

class ViewController: UIViewController {

    private var imageArray:Array<UIImageView> = Array()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupAnimation()
    }
    
    private func setupAnimation() {
        let viewWidth:CGFloat = self.view.frame.width
        let viewHeight:CGFloat = self.view.frame.height
        //インスタンスを生成
        for i in 0..<9 {
            let imageView:UIImageView = UIImageView()
            imageView.image = UIImage(named: "tax")
            imageView.contentMode = .scaleAspectFit
            imageView.frame.size = CGSize(width: 200, height: 200)
            imageArray.append(imageView)
            self.view.addSubview(imageArray[i])
        }
        //アニメーション
        //１列目
        imageArray[0].center = CGPoint(x: -viewWidth / 2, y: viewHeight * 0.6)
        imageArray[1].center = CGPoint(x: 0, y: viewHeight * 0.3)
        imageArray[2].center =  CGPoint(x: viewWidth / 2, y: 0)
        
        //2列目
        imageArray[3].center = CGPoint(x: -viewWidth / 2, y: viewHeight * 1.2)
        imageArray[4].center = CGPoint(x: 0, y: viewHeight * 0.9)
        imageArray[5].center = CGPoint(x: viewWidth / 2, y: viewHeight * 0.6)
        imageArray[6].center = CGPoint(x: viewWidth, y: viewHeight * 0.3)
        
        //３列目
        imageArray[7].center = CGPoint(x: viewWidth / 2, y: viewHeight * 1.2)
        imageArray[8].center = CGPoint(x: viewWidth, y: viewHeight * 0.9)
        
        //アニメーションの設定
        //一定の速さで繰り返しのアニメーション表示を行う
        UIView.animate(withDuration: 2, delay: 0.0, options: [.repeat, .curveLinear], animations: {
            //１列目
            self.imageArray[0].center = CGPoint(x: 0, y: viewHeight * 0.3)
            self.imageArray[1].center = CGPoint(x: viewWidth / 2, y: 0)
            self.imageArray[2].center = CGPoint(x: viewWidth, y: -viewHeight * 0.3)
            
            //2列目
            self.imageArray[3].center = CGPoint(x: 0, y: viewHeight * 0.9)
            self.imageArray[4].center = CGPoint(x: viewWidth / 2, y: viewHeight * 0.6)
            self.imageArray[5].center = CGPoint(x: viewWidth, y: viewHeight * 0.3)
            self.imageArray[6].center = CGPoint(x: viewWidth * 1.5, y: 0)
            
            //３列目
            self.imageArray[7].center = CGPoint(x: viewWidth, y: viewHeight * 0.9)
            self.imageArray[8].center = CGPoint(x: viewWidth * 1.5, y: viewHeight * 0.6)
        },completion:nil)
    }

}