An intensity graph takes a 2D-array input where the X-axis is defined by the number of columns and the Y-axis is defined by the number of rows. The color plotted as a Z-value is the value at indices (x,y) of the array.
So, generally, you cannot simply swap the y and z values. The X and Y values are typically systematically scanned from a range of values with constant steps while the Z values can take any arbitrary value.
Hopefully that information helps you.
Marc Dubois
