D<-matrix(c(1,1,1,2,3,4,2,3,4),nr=3,nc=3)
layout(D)
layout.show(9)
为何输出的图形不是3行3列呢？

E<-matrix(c(0.125,0.375,0.375,0.125,0.625,0.125,0.125,0.125,0.125,0.625,0.125,0.125,0.25,0.25,0.25,0.25),ncol=4,byrow=T)
layout(E)
layout.show(16)
为何显示：
错误于layout(E) :
  格式矩阵至少要有对{1..n}里每一个值的参考值；但这里n = 0
这是啥意思啊。敬请指教！！