T函数产生方法

代码说明：

说明：  由于vc系统随机函数产生的数均匀分布,有时要用到正态分布和分布,这是两个小函数,让你们见笑了(vc system because of the random number function evenly distributed, and sometimes we had to use normal distribution and distribution, which is two small functions so that you laughed at the)