It (almost) always helps to read the "Help" for LabVIEW functions. This is from the Help for Peak Detector: "threshold instructs the VI to ignore peaks and valleys that are too small. The VI ignores peaks if the fitted amplitude is less than threshold. The VI ignores valleys if the fitted trough is greater than threshold."
You used a threshold of 0.005. All of your valleys are >0.005. Hence, as documented, "The VI ignores valleys if the fitted trough (approximatly 2.4) is greater than threshhold (0.005)".
Try using a threshold of 2.5. You will get 5 peaks and 5 valleys. Alternatively, zero-mean your function and use a threshold of 0.005.
Bob Schor
