How to get a coordinate value for a specific point of a curve

[happybird]

Hellow! i 'd like to get the coordinate value for a specific point of a curve in XY graph,for example,a series of peak point of a wave form,i try to use cursor to measure the peak,but i know it is not accurate,are there any way to realize it? thanks!

[winterishere8]

Lets say you have 10 points (Y-axis) and you want to measure the first three peak points. Take the data as an array and extract the first 3 maximum points.
Make a 2-D array using your data as the first column (Y-axis), and Xaxis as your 2nd column, then sort the 2-D array using your first column. Then extract the first 3 data sets. Hope this helps.

[Philip_Courtois]

If you have the Full or the Professional Development package of LabVIEW, you have a VI called �Peak Detect.vi� that will find all the peaks in your array.

Notice that finding the peaks is not similar to finding the largest Y values. In the attached images you can see that the Y value at index 8 is much lower than most of the other Y values in the data set, but it is still considered a peak because of the surrounding two values are lower.

I hope this answered your question.

Best regards,
Philip C.
Applications Engineer
National Instruments
www.ni.com/ask