Flipping a matrix diagonally

I would like to flip a matrix that I have diagonally from left to right as shown in the image. Is there a command or a simple way to do this? The other two ends of my matrices have the correct values so I do not want them to move

Answer 1

[DGM]

I'm assuming you want to flip the whole matrix diagonally

To flip about the southeast-northwest diagonal is just transpose:

A = magic(5)

A = 5×5

17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9

A.'

ans = 5×5

17 23 4 10 11 24 5 6 12 18 1 7 13 19 25 8 14 20 21 2 15 16 22 3 9

So then flipping about the opposite diagonal is just a matter of flipping one axis:

fliplr(fliplr(A).')

ans = 5×5

9 3 22 16 15 2 21 20 14 8 25 19 13 7 1 18 12 6 5 24 11 10 4 23 17

[Curtis Lam]

I think this is close but for some reason it's not working correctly for me.. right now I have a 500x500 matrix with vertices ( the corners) looking like

[ 147 278

457 13.6]

and i want to flip/rotate the matrix so that the corners are these values so i know that the matrix is accurately representative of the raw data with corners like so:

[457 147

278 13.6]

I think I may have worded the question incorrectly but your answer might be right for the question i asked.

[DGM]

I don't see how that's possible with any rigid transformation like a flip/transpose/rotation. The fact that adjacent corners become opposite corners leads me to question what you expect the interior of the array to look like.

Consider:

A = [147 278;
    457 13];

becomes

B = [457 147;
    278 13];

B is basically A' with the top row flipped. What if there were more rows?

A = [147 156 278;
    124 456 583;
    457 46 13];

We could transpose and then ...? How do you half-flip a row?

B = [457 124 147;
    ??? ??? ???;
    278 583 13];

I'm not really sure what this transformation is supposed to do. I mean anything is possible with interpolation, but the question is what it means.

Answer 2

[KSSV]

A = rand(5) ; 
n = size(A,1) ; 
v = A(1:n+1:end)  ; 
A(1:n+1:end)  = fliplr(A(1:n+1:end))

Also read about diag.

[Isobel]

This flips the diagonal, not the matrix along the diagonal.