"Flipping" a matrix over its diagonal. The rows and columns get swapped.
The symbol is a "T" placed above and to the right like this: AT
Example: the value in the 1st row and 3rd column ends up in the 3rd row and 1st column.
The values on the main diagonal stay the same.
The transpose of a transpose gets us back to where we started.
(Animation courtesy Wikpedia user LucasVB)
Definition of
Transpose (matrix)
