I want to plot my values in Y-Axis such that the lowest stays in the upper and the maximum stays at the bottom without changing the sign. How can I do it? Thank you very much.
That's not possible in Prime, but in (real) Mathcad (15 and before) it is possible without problems by changing the axis limits accordingly.
You can do it in Prime but you would have to use the new chart component which was introduced with Prime 5. by defining Ymin and Ymax accordingly.
Unfortunately this chart component otherwise is just a piece of crap.