Zero-phase Butterworth bandstop filter. Default 59–61 Hz removes North-
American AC mains hum (60 Hz); use 49–51 Hz for European mains.
Usage
buttbs(x, fs, low = 59, high = 61, order = 4L)
Arguments
- x
Numeric vector.
- fs
Sampling frequency (Hz).
- low
Lower cutoff (Hz, default 59).
- high
Upper cutoff (Hz, default 61).
- order
Filter order (default 4).
Value
List with filtered (numeric vector), fs, order, name.
Examples
# \donttest{
if (requireNamespace("signal", quietly = TRUE)) {
set.seed(1)
t <- seq(0, 1, length.out = 1000)
x <- sin(2 * pi * 10 * t) + sin(2 * pi * 60 * t)
y <- buttbs(x, fs = 1000) # remove 60 Hz mains
length(y$filtered)
}
#> [1] 1000
# }