bessel function takes a multi-channel signal and applies a bessel lowpass filter to the signal.

bessel(df, sr, cutoff_freq, order = 8)

Arguments

df

dataframe. The input multi-channel signal. The first column is timestamps in POSXlct format. The rest columns are signal values.

sr

number. Sampling rate in Hz of the input signal.

cutoff_freq

number. The lowpass cutoff frequency in Hz.

order

number. The order of the filter. Default is 8.

Value

dataframe. Filtered signal.

Details

This function filters the input multi-channel signal by applying a bessel lowpass filter. See wiki for the explanation of the filter. The filter was implemented with the same implementation as in MATLAB.

How is it used in MIMS-unit algorithm?

This function has been considered as one of filtering options during the development of MIMS-unit algorithm. But the released version of MIMS-unit algorithm does not use this function for filtering.

See also

Other filtering functions: bandlimited_interp(), iir(), remove_average()

Examples

# Use sample data df = sample_raw_accel_data # View input illustrate_signal(df, plot_maxed_out_line = FALSE)
# Apply filtering output = bessel(df, sr=80, cutoff_freq=2, order=8) # View output illustrate_signal(output, plot_maxed_out_line = FALSE)