选择箱量（等价于窗宽） Simple rule of thumb for small Histogram of income datasets(approx.100 or less) is: of bins =2vn For larger samples,the car package for R implements Freedman and Diaconis (1981)recommended formula from the n.bins function: 5000 10000150002000025000 #of bins= n3(max-tw 2(Q3-Q1) >hist(income,nclass=n.bins(income))选择箱量（等价于窗宽）