I got a matrix of numbers:

```
x<-c(1,1,1,1,2,2,2,3,3,4)

```

I need a version like this:

```
x<-c(4,4,4,4,3,3,3,2,2,1)

```

It is just a reversed version of the first array. Are there any efficient ways of getting this other than maybe a brute force loop?