Matrix Flipping (Matlab Style)

Flip matrices up and down or left and right; or circulating indices per dimension.

flipdim(a, dim)
flipud(a)
fliplr(a)
circshift(a, sz)

Arguments

a

numeric or complex matrix

dim

flipping dimension; can only be 1 (default) or 2

sz

integer vector of length 1 or 2.

Details

flipdim will flip a matrix along the dim dimension, where dim=1 means flipping rows, and dim=2 flipping the columns.

flipud and fliplr are simply shortcuts for flipdim(a, 1) resp. flipdim(a, 2).

circshift(a, sz) circulates each dimension (should be applicable to arrays).

Value

the original matrix somehow flipped or circularly shifted.

Examples

a <- matrix(1:12, nrow=3, ncol=4, byrow=TRUE)
flipud(a)
#>      [,1] [,2] [,3] [,4]
#> [1,]    9   10   11   12
#> [2,]    5    6    7    8
#> [3,]    1    2    3    4
fliplr(a)
#>      [,1] [,2] [,3] [,4]
#> [1,]    4    3    2    1
#> [2,]    8    7    6    5
#> [3,]   12   11   10    9

circshift(a, c(1, -1))
#>      [,1] [,2] [,3] [,4]
#> [1,]   10   11   12    9
#> [2,]    2    3    4    1
#> [3,]    6    7    8    5
v <- 1:10
circshift(v, 5)
#>  [1]  6  7  8  9 10  1  2  3  4  5