CFD Online Discussion Forums - reverse xy axis in gnuplot

hi everyone!
now I've got a file looking like this

Code:

        

       A        B        C        D        E

a        1        2        4        0        2

b        3        4        5        6        8

c        3        5        3        5        7

d         1        4        6        9        8

e        3        4        7        9        0

by default splot 'file' matrix and set pm3d map use ABCED as the x axis and abcde as the y axis.
how can I reverse this and make ABCDE the y axis and abcde the x axis?

I realize that this maybe barely related to openfoam, but I've got nowhere else to ask this.
thanks in advance.