Here is what I am trying to do.
I have a list of numerical data taken from a measurement that is not sorted and can't be sorted. Here is the reason why. The values start near 0 then increase up to a max number then decrease back down to zero and do the same thing on the negative end of things. I have to find a point on the increasing positive side (e.g. 2000) and then that same point on the decreasing positive side. The number it finds just needs to be the closest match to the number we are looking for.

The same thing needs to be done on the negative side as well.

Below is an example of two points that would be on the curve. Think of the max in the upper right where the two lines meet being ~10000 and the arrows being at a value close to the variable we are looking for (2000).

Any help would be appreciated

hysteresis.gif