Hello, I apologize for the delayed response.
I took a look at your VI. In its current state, you will not be able to extract Y values for X values in-between those that you plotted. The XY graph is simply connecting your points to provide a visual representation. No real data exists between the points that you plotted. What you will need to do is first use one of LabVIEW's built-in curve fitting functions to fit a curve to your randomized data. These functions are located on the Analyze >> Mathematics >> Curve Fitting palette. Once you fit a curve to your data, you will be able to trace the curve with your cursor. You can observe the XY-values that the cursor passes over by displaying the cursor legend. Right click the XY-graph and select Visible Items >> Cursor Legend. You may also want to consider using LabVIEW's mathematics functions to evaluate the x-values you are interested in. One solution would be to vertically shift your best-fit curve by the threshold value and evaluate the zeros of the curve using LabVIEW's built-in functions. These functions can be found on the Analyze >> Mathematics >> Zeros palette. I hope this helps! If you have further questions, let me know. Matthew C Applications Engineer National Instruments
