Two vectors same length

Hey guys,

Is there a way to force one vector to the same as another? I am trying to plot a force-strain curve, and there comes a point where the strain remains const and the force values continue to change until the data stops. I used the unique function to stop the strain values from repeating, but I'm not quite sure how to stop the corresponding force values to stop too. Any help would be greatly appreciated. thanks!

[Azzi Abdelmalek]

post a small example