如matrix(c(1:8),2)*matrix(c(8:1),2)
> matrix(c(1:8),2)
[,1] [,2] [,3] [,4]
[1,]1357
[2,]2468
>matrix(c(8:1),2)
[,1] [,2] [,3] [,4]
[1,]8642
[2,]7531
> matrix(c(1:8),2)*matrix(c(8:1),2)
[,1] [,2] [,3] [,4]
[1,]8 18 20 14
[2,] 14 20 188
求和:f<-function(x) {
if(x==1) 1
else x+f(x-1) }
或者尾递归:ff<-function(x,m=0){
if(x == 0) m
else ff(x-1,m+x) }
求阶乘:g<-function(x) {
if(x ==1) 1
else x*g(x-1) }
或者尾递归:gg<-function(x,acc=1){
if(x ==1) acc
else gg(x-1,acc*x) }