godamchen 刚刚开始用R和s-plus,查不到解方程组的命令,实在不得要领,急死了,帮帮忙,谢谢!! 其实就是简单的moment method求2参数weibull的变量,s-plus上的快捷键好像也没有, mean(data)=lambda*(gamma(1+1/tu)) var(data)=lambda^2*(gamma(1+2/tu)-(gamma(1+1/tu))^2)
rtist pencil & paper for analytic solution; for numerical solution, see http://cos.name/bbs/read.php?tid=7199