.audSpectrogram: Auditory spectrogram per sound

Description

Internal soundgen function.

Usage

.audSpectrogram(
  audio,
  step = 1,
  dynamicRange = 80,
  nFilters,
  minFreq = 20,
  maxFreq = audio$samplingRate/2,
  minBandwidth = 1,
  plot = TRUE,
  osc = c("none", "linear", "dB")[2],
  heights = c(3, 1),
  ylim = NULL,
  yScale = "bark",
  contrast = 0.2,
  brightness = 0,
  maxPoints = c(1e+05, 5e+05),
  padWithSilence = TRUE,
  colorTheme = c("bw", "seewave", "heat.colors", "...")[1],
  col = NULL,
  extraContour = NULL,
  xlab = NULL,
  ylab = NULL,
  xaxp = NULL,
  mar = c(5.1, 4.1, 4.1, 2),
  main = NULL,
  grid = NULL,
  width = 900,
  height = 500,
  units = "px",
  res = NA,
  ...
)

Arguments

audio: a list returned by readAudio
step: step, ms (determines time resolution). step = NULL means no downsampling at all (ncol of output = length of input audio)
dynamicRange: dynamic range, dB. All values more than one dynamicRange under maximum are treated as zero
nFilters: the number of filters (determines frequency resolution)
minFreq, maxFreq: the range of frequencies to analyze
minBandwidth: minimum filter bandwidth, Hz (otherwise filters may become too narrow when nFilters is high)
plot: should a spectrogram be plotted? TRUE / FALSE
osc: "none" = no oscillogram; "linear" = on the original scale; "dB" = in decibels
heights: a vector of length two specifying the relative height of the spectrogram and the oscillogram (including time axes labels)
ylim: frequency range to plot, kHz (defaults to 0 to Nyquist frequency). NB: still in kHz, even if yScale = bark, mel, or ERB
yScale: scale of the frequency axis: 'linear' = linear, 'log' = logarithmic (musical), 'bark' = bark with hz2bark, 'mel' = mel with hz2mel, 'ERB' = Equivalent Rectangular Bandwidths with HzToERB
contrast: spectrum is exponentiated by contrast (any real number, recommended -1 to +1). Contrast >0 increases sharpness, <0 decreases sharpness
brightness: how much to "lighten" the image (>0 = lighter, <0 = darker)
maxPoints: the maximum number of "pixels" in the oscillogram (if any) and spectrogram; good for quickly plotting long audio files; defaults to c(1e5, 5e5)
padWithSilence: if TRUE, pads the sound with just enough silence to resolve the edges properly (only the original region is plotted, so the apparent duration doesn't change)
colorTheme: black and white ('bw'), as in seewave package ('seewave'), or any palette from palette such as 'heat.colors', 'cm.colors', etc
col: actual colors, eg rev(rainbow(100)) - see ?hcl.colors for colors in base R (overrides colorTheme)
extraContour: a vector of arbitrary length scaled in Hz (regardless of yScale!) that will be plotted over the spectrogram (eg pitch contour); can also be a list with extra graphical parameters such as lwd, col, etc. (see examples)
xlab, ylab, main, mar, xaxp: graphical parameters for plotting
grid: if numeric, adds n = grid dotted lines per kHz
width, height, units, res: graphical parameters for saving plots passed to png
...: other graphical parameters