Finding minimum from a curve

[JoshMonkey]

I've gathered a 1D array of data points that fits a curve (similar to a sine curve). I'm now looking for a method to find all the minimum or maximum points from the curve. Have been looking in the Analyze but couldn't find any useful VI. Anyone know how I can get it done?

Also what if my data is a flatline (straight)? How do I "toogle" between the curve and line?

[JoshMonkey]

Just found this thread with similar problem: "How to see the peak values in a chart?" and my initial idea aws pretty similar to one of the suggested method:
1. find the best fit curve
2. use the derivative to find the tangential change hence locating the min/max points.

I'll try this method and see if it works. 🙂

[djs_at_eaton]

I recently had a similar problem. The attached VI will accept a 1D array and return 4 arrays. The arrays are the values of the negative and positive peaks and the indicies of both. It's a brute force method, but it works.

It's large because I left the original data as the default value. Emptying the input array and making it the default value will cut the size.