seewave (version 2.2.3)

squarefilter: Frequency square filter

Description

This function prepares the amplitude profile of a square frequency filter.

Usage

squarefilter(f, from = NULL, to = NULL, bandpass = TRUE, wl = 1024)

Value

The function returns a two-column matrix, the first column is the frequency in kHz and the second column is the amplitude of the filter (frequency response of the filter).

Arguments

f

a numeric vector of length 1 for the sampling frequency of the object to be filtered (in Hz).

from

a numeric vector for the start frequencies (in Hz) where to apply the filter.

to

a numeric vector of the end frequencies (in Hz) where to apply the filter.

bandpass

if TRUE a band-pass filter is prepared between start and end frequencies (arguments from and to), if FALSE a bandstop filter is prepared.

wl

window length of the impulse filter (even number of points).

Author

Laurent Lellouch

See Also

fir, drawfilter, ffilter, combfilter, bwfilter

Examples

f <- 44100
a <- noisew(f = f, d = 1)
p <- squarefilter(f, from = c(100, 1000, 4000), to = c(500, 3000, 8000))
plot(p, type="l")
h <- fir(a, f = f, custom = p, wl = 1024, output = 'Wave')
spectro(h)