箱线图，或称盒须图，用5个点即可以对给定数据集做出简单总结，这5个点从包括最大值、上四分位数、中位数、下四分位数、最小值。-boxplot.m, used to draw the box plot for a given data set，can make a brief summary by just five nodes, including the maximum value, the upper quartile, the median, lower quartile, and the minimum.