I have a data here, I want to make sense of Lowpass filtering function in Mathematica.I do not fully understand units of cut off frequency in this option since the data is in frequency space. What I would like to do is to eliminate the small oscillation. It turns out that the Lowpass filter is doing its job
I have done the following.
ListPlot[data, PlotRange -> All, Joined -> True]
and secondly,
ListPlot[Transpose[{data[[All, 1]],
LowpassFilter[data[[All, 2]], 0.1]}], Joined -> True,
PlotRange -> All, AxesLabel -> {"Frequency (Hz)", "Scaled intensity with offset correction"}]
Here; what is the unit of the cut off frequency which is "0.1".
I know that I should define a sample rate in order to know the cut-off frequency. But from the definition of Lowpass filtering, I saw that the sample rate is automatically defined.
Could anyone please explain me how do I make sense of the cut-off frequency 0.1 and its unit in this example?
LowpassFilter[]
expects time series data. If your data is given already in the frequency domain you usually just multiply your spectrum by the filter frequency response. $\endgroup$MovingAverage
: at least it will be clear what you're doing. Or you could do some kind of fit. $\endgroup$