y coordinate

• The contents of these files are self - explanatory and simply serve to animate the " fluttering " of the butterflies by cycling through different size versions of the same image , and moving the butterflies up the screen by decrementing their y coordinate
  这些文件的内容无须解释，它们只用于实现蝴蝶的振翅（通过循环显示不同尺寸的同一图像） ，并通过递减y坐标让蝴蝶飞出屏幕。
• The magic of plotting graphs lies in being able to scale a given data value from one range to another ; that is , given a set of values like 10 , 20 , 30 , you should be able to decide exactly which points x and y coordinates on a 2 - d plane represent the data values 10 , 20 , and 30
  绘图的奇妙之处在于能够将某一个给定数据值从一个范围按比例缩放到另一个范围中，也就是说，如果给定一组值，如{ 10 , 20 , 30 } ，那么您应该能够确定2 - d飞机上具体哪些点（ x坐标和y坐标）表示的是10 、 20和30这些数据值。