manipulating XY data

[Joe_John]

I'm working on an application for a press force monitor. The data I collect is force versus distance. Column one is the distance the press moves and column two is the force from the load cell. I need to find a way to stretch or shrink the force data to be between a desired distance.  As an example, if I collect force between 10mm and 20mm I want to find a way to manipulate the data  to stretch it between 5mm and 30mm.  It would also be nice if I could select how many data points are required between the desired distance. I've racked my brain for days trying to figure this out. I'd love to get some help!

The problem I'm having is comparing one press cycle to another. If I put in a "Master" part, I need to compare all other parts to this master. The problem occurs when the press cycle occurs at a different height then the master or if it takes longer. The profiles between the master and the tested parts are the same but one is stretched because it took a little longer. I need to find a way to make the two cycles comparable by taking the force data from the tested part and either compress or stretch it to equal the same distance travelled by the master part.

Basically I need to find a way to manipulate the x data from an xy graph so I can overlay two pieces of data that may not have the same number of points but start on the same x plot and end on the same x plo.

[Jared_B]

Joe John,

You might be able to normalize the waveform and then scale the data from there to achieve the results you are wanting.  I understand what you are wanting but not sure if you are looking for a linear scale or exponential, etc etc.  Normalizing the waveform might be the easiest method because it will take the waveform to a -1 to +1 scale.  From this scale you'd have a constant scale/offset factor that you could use to stretch the data among the 5mm and 30mm span in whichever method works best for you.

[Joe_John]

Do you have an example on how to do that?

[Jared_B]

Joe John,

While I don't have an example on how to do everything specified.  There is an example for the Normalize Waveform.  Then you'd just use some scaling and/or array manipulation VIs to get it to what you want.  Shouldn't be too difficult an algorithm.