How to create one plot with two x axes ?

How can I create a single plot with 2 x axis that correspond to the data? let say one axis up and one down. Thanks

Answer 1

[Walter Roberson]

See the File Exchange contribution "plotxx"

[Elad]

I want to have only one plot and that both x axes would correspond to its data, plotxx would give me 2 different plots.

[Walter Roberson]

plot NaN, NaN in the second plot, and set() its XLim and Direction to be what you want to see.

If you have a requirement to use only one axes object instead of two, then you will have to line() and text() the additional axes into place, and you will need to add action post-filters for both zoom and pan so that you can redraw that information according to the new axis bounds. MATLAB does not offer any mechanism for arbitrary positioning of an object that acts like an axes: MATLAB only supports edge axes (identical on two sides if both sides are shown.)

[Elad]

Oh, ok. Thanks for the answer.