How to remove Drift in the periodic signal after numerical Integration

Hello to all mathworks fellows,

I am trying to numerically integrate a data using cumtrapz function. (the data file attached)

I have the attached graphs of input, integrated output and fft of the input as well. One can clearly observe the drift in the integrated output. How to troubleshoot it?

Can anyone help me in this regard please?

Thanks in anticipation.

Answer 1

[Bjorn Gustavsson]

The function detrend was made for this type of task. It should work like this:

y_detrended = detrend(y);

If you have a higher-order polynomial trend it copes too:

y_cubic_dt = detrend(y,3);

HTH