flipping a maximum point to become a minimum of the same size

having the attached data, how can we flip the points indicated in red (assumed as maximums) to become minimums of the same size?

[Dyuman Joshi]

It's not clear what is the output you want to obtain. Can you visualize it via an example and show?

Answer 1

[KSSV]

You can chnage the sign right?

plot(xup,-yup)

[Salma fathi]

Thank for the swift reply. I am not asking how to flip them around the x or the y axis. I am trying to find away to flip each maximum peak for eaxmple 180 degrees around itself, for it to become a minimum. Or to have the peak directed towards the other side.