twopoint

代码说明：

  根据样本估计密度曲线的方法，也就是pavzen窗函数法，采用正态窗函数，先画直方图，在估计平滑的密度曲线(Estimated based on the sample density curve method, which is pavzen window function method, using normal windows function, the first histogram drawn in the estimated density curve smoothing)