画出数据的histtogram频率分布图及其概率密度函数，其中概率分布图的小区间范围以及整个数据区间的范围均可调-Plot the histtogram and probability density function (PDF) of statistic data which the whole range and subrange of the plot can be adjusted.

偏t分布的概率密度函数(pdf)、累积分布函数(CDF)、分位数(quantiles)计算以及生成随机数的matlab代码。-Matlab code for calculating probability density function, cumulative distribution function, quantiles of the skewed-t distribution and generating the random samples