corresponding trends plot in data series

Hello everyone

I plotted under matlab R2021a my data series (figure 1) and I would like to know how I can plot the corresponding trends to my data series as shown in black on the example of figure 2

[Mathieu NOE]

hello

the trend is basically a low pass filtered version of the raw data

one method is to smooth the data , for example with smoothdata (try with 'gaussian' window)