R语言中,cbind和rbind区别和作用

cbind： 根据列进行合并，即叠加所有列，m列的矩阵与n列的矩阵cbind()最后变成m+n列，合并前提：cbind(a, c)中矩阵a、c的行数必需相符

rbind： 根据行进行合并，就是行的叠加，m行的矩阵与n行的矩阵rbind()最后变成m+n行，合并前提：rbind(a, c)中矩阵a、c的列数必需相符
> a <- matrix(1:12, 3, 4)
> print(a)
[,1] [,2] [,3] [,4]
[1,] 1 4 7 10
[2,] 2 5 8 11
[3,] 3 6 9 12
>
> b <- matrix(-1:-12, 3, 4)
> print(b)
[,1] [,2] [,3] [,4]
[1,] -1 -4 -7 -10
[2,] -2 -5 -8 -11
[3,] -3 -6 -9 -12
>
> x=cbind(a,b)
> print(x)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8]
[1,] 1 4 7 10 -1 -4 -7 -10
[2,] 2 5 8 11 -2 -5 -8 -11
[3,] 3 6 9 12 -3 -6 -9 -12
>
> y=rbind(a,b)
> print(y)
[,1] [,2] [,3] [,4]
[1,] 1 4 7 10
[2,] 2 5 8 11
[3,] 3 6 9 12
[4,] -1 -4 -7 -10
[5,] -2 -5 -8 -11
[6,] -3 -6 -9 -12
>
>
> c <- matrix(-1:-20, 4, 5)
> print(c)
[,1] [,2] [,3] [,4] [,5]
[1,] -1 -5 -9 -13 -17
[2,] -2 -6 -10 -14 -18
[3,] -3 -7 -11 -15 -19
[4,] -4 -8 -12 -16 -20
>
> x2=cbind(a,c)
Error in cbind(a, c) : 矩阵的行数必需相符(见arg2)
> print(x2)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9]
[1,] 1 4 7 10 -1 -4 -7 -10 -13
[2,] 2 5 8 11 -2 -5 -8 -11 -14
[3,] 3 6 9 12 -3 -6 -9 -12 -15
>
> y2=rbind(a,c)
Error in rbind(a, c) : 矩阵的列数必需相符(见arg2)
> print(y2)
Error in print(y2) : 找不到对象’y2′
>