cepstro {seewave} | R Documentation |
This function returns a two-dimension cepstrographic representation of a time wave. The function corresponds to a short-term cepstral transform. An amplitude contour plot can be overlaid.
cepstro(wave, f, wl = 512, ovlp = 0, plot = TRUE, grid = TRUE, scale = TRUE, cont = FALSE, collevels = seq(0, 1, 0.01), palette = rev.heat.colors, contlevels = seq(0, 1, 0.01), colcont = "black", colbg="white", colgrid = "black", colaxis = "black", collab = "black", plot.title = title(main = "", xlab = "Time (s)", ylab = "Quefrency (kHz)"), scalelab = "Amplitude", scalefontlab = 1, scalecexlab = 0.75, axisX = TRUE, axisY = TRUE, ...)
wave |
data describing a time wave or a Sample
object generated loading a wav file with loadSample
(package sound). |
f |
sampling frequency of wave (in Hz).
Does not need to be specified
if wave is a Sample object. |
wl |
if at is not null, length of the window for the analysis
(even number of points, by defaults = 512). |
ovlp |
overlap between two successive windows (in %). |
plot |
logical, if TRUE plots the cepstrogram
(by default TRUE ). |
grid |
logical, if TRUE plots a y-axis grid
(by default TRUE ). |
scale |
logical, if TRUE plots a dB colour scale on the right
side of the cesptrogram (by default TRUE ). |
cont |
logical, if TRUE overplots contour lines on the cepstrogram
(by default FALSE ). |
collevels |
a set of levels which are used to partition the amplitude range of the cepstrogram (in dB). |
palette |
a color palette function to be used to assign colors in
the plot, see Details . |
contlevels |
a set of levels which are used to partition the amplitude range for contour overplot (in dB). |
colcont |
colour for cont plotting. |
colbg |
background colour. |
colgrid |
colour for grid plotting. |
colaxis |
color of the axes. |
collab |
color of the labels. |
plot.title |
statements which add titles to the plot. |
scalelab |
amplitude scale label. |
scalefontlab |
font of the amplitude scale label. |
scalecexlab |
cex of the amplitude scale label. |
axisX |
if TRUE plots time X-axis (by default TRUE ). |
axisY |
if TRUE plots frequency Y-axis (by default TRUE ). |
... |
other contour graphical parameters. |
It is unfortunately not possible to turn the y-axis to a frequency scale.
See spectro
for the use of the graphical arguments.
When plot
is FALSE
, a matrix is returned with the successive
cepstral profiles computed along time.
This function is based on ceps
.
Jerome Sueur sueur@mnhn.fr.
Oppenheim, A.V. and Schafer, R.W. 2004. From frequency to quefrency: a history of the cepstrum. Signal Processing Magazine IEEE, 21: 95-106.
data(sheep) cepstro(sheep,f=8000)