Scale the axis in a contourf plot/ change axis location

I have a contour plot with positive value for x axis and negative value for y axis, both start from the 0. I want my x axis to be on top, just to make sure scaling make sense. Appreciate any help.

Answer 1

[M]

Maybe something like this :

contour(...);
ax=gca;
ax.XAxisLocation='top';

[Nahid Taheri]

I tried that, but it did not work. Also, do you know how we can select the color on the color bar?