.bandpass: Bandpass filter per sound

Description

Internal soundgen function

Usage

.bandpass(
  audio,
  lwr = NULL,
  upr = NULL,
  action = c("pass", "stop")[1],
  dB = Inf,
  bw = 0,
  na.rm = TRUE,
  normalize = FALSE,
  plot = FALSE,
  width = 900,
  height = 500,
  units = "px",
  res = NA,
  ...
)

Arguments

audio: a list returned by readAudio
lwr, upr: cutoff frequencies, Hz. Specifying just lwr gives a high-pass filter, just upr low-pass filter with action = 'pass' (or vice versa with action = 'stop'). Specifying both lwr and upr a bandpass/bandstop filter, depending on 'action'
action: "pass" = preserve the selected frequency range (bandpass), "stop" = remove the selected frequency range (bandstop)
dB: a positive number giving the strength of effect in dB (defaults to Inf - complete removal of selected frequencies)
bw: bandwidth of the filter cutoffs, Hz. Defaults to 0 (abrupt, step function), a positive number corresponds to the standard deviation of a Gaussian curve, and two numbers set different bandwidths for the lower and upper cutoff points
na.rm: if TRUE, NAs are interpolated, otherwise they are preserved in the output
normalize: if TRUE, resets the output to the original scale (otherwise filtering often reduces the amplitude)
plot: should a spectrogram be plotted? TRUE / FALSE
width, height, units, res: graphical parameters for saving plots passed to png
...: other graphical parameters passed to plot() as well as to meanspec