L系统单一规则生成Koch曲线源代码，可通过改变初始元、生成元、角度和压缩因子等生成要素绘制出许多“简单”分形图形。（非原创，原程序存在错误，我进行了修改，可能扔存在错误。）-L system single rule Koch curve generated source code can be changed by the initial yuan, generators, angle and compression factor generated elements drawn many &