Butterworth bandpass filter

Design and apply a zero-phase Butterworth bandpass filter to a signal. Wraps gsignal::butter() and gsignal::filtfilt() for convenience.

Usage

bandpass_filter(x, flp, fhi, delt, order = 2)

Arguments

x

Numeric vector. Signal to be filtered.

flp

Numeric. Low-pass cutoff frequency (Hz).

fhi

Numeric. High-pass cutoff frequency (Hz).

delt

Numeric. Sampling interval in seconds (i.e. TR for fMRI).

order

Integer. Filter order. Default is 2.

Value

Numeric vector. Zero-phase filtered signal, same length as x.

Examples

set.seed(1)
x <- rnorm(200)
x_filt <- bandpass_filter(x, flp = 0.01, fhi = 0.1, delt = 2, order = 2)