Hi,
I think, there is no way to use floating point indices for the 2D-Matrix.
What I would do is to scale the x/y-coordinates.
for example: 0 is element 0,
0.25 is element 1
0.5 is element 2
and so on....
you can scale the X and Y-axis of the graph with the same factor, so that the axes are correct labeld.
I hope this helps..
regards,
Peter Weber
Ni Germany