spectro {seewave} | R Documentation |
This functions returns a two-dimension spectrographic representation of a time wave. The function corresponds to short-term Fourier transform. An amplitude contour plot can be overlaid.
spectro(wave, f, wl, zp = 0, ovlp = 0, plot = TRUE, grid = TRUE, osc = FALSE, scale = TRUE, cont = FALSE, collevels = seq(-30, 0, 1), palette = spectro.colors, contlevels = seq(-30, 0, 10), colcont = "black", colgrid = "black", plot.title = title(main = "", xlab = "Time (s)", ylab = "Frequency (kHz)"), scalelab = "Amplitude\n(dB)", scalefontlab = 1, axisX = TRUE, axisY = TRUE, ...)
wave |
data describing a time wave. |
f |
sampling frequency of wave . |
wl |
length of the window for the analysis (even number of points). |
zp |
zero-padding (even number of points), see Details . |
ovlp |
overlap between two successive windows (in %). |
plot |
logical, if TRUE plots the spectrogram
(by default TRUE ). |
grid |
logical, if TRUE plots a y-axis grid
(by default TRUE ). |
osc |
logical, if TRUE plots an oscillogram beneath
the spectrogram (by default FALSE ). |
scale |
logical, if TRUE plots a dB colour scale on the right
side of the spectrogram (by default TRUE ). |
cont |
logical, if TRUE overplots contour lines on the spectrogram
(by default FALSE ). |
collevels |
a set of levels which are used to partition the amplitude range of the spectrogram (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. |
colgrid |
colour for grid plotting. |
plot.title |
statements which add titles to the plot. |
scalelab |
amplitude scale label. |
scalefontlab |
font of the amplitude scale label. |
axisX |
logical, if TRUE plots X-axis (by default TRUE ). |
axisY |
logical, if TRUE plots Y-axis (by default TRUE ). |
... |
other contour and oscillo
graphical parameters. |
A Hanning function is applied to the analysis window.
zp
adds 0 values on both sides of the analysis window. This increases
frequency resolution without altering time resolution.
Any colour palette can be used. In particular, it is possible to use other palettes coming with
seewave: rev.heat.colors
, rev.terrain.colors
, rev.topo.colors
,
rev.cm.colors
corresponding to the reverse of heat.colors
,
terrain.colors
, topo.colors
, cm.colors
.
Use locator
to identify points.
If plot
is FALSE
, this function returns a matrix. Each column
corresponds to a Fourier transform of length wl
.
This function is based on fft
, contour
and
filled.contour
Jérôme Sueur jerome.sueur@ibaic.u-psud.fr and Caroline Simonis-Sueur csimonis@mnhn.fr.
Hopp, S. L., Owren, M. J. and Evans, C. S. (Eds) 1998. Animal acoustic communication. Springer, Berlin, Heidelberg.
spectro3D
, oscillo
, dBscale
, fft
.
data(tico) data(peewit) data(pellucens) data(alauda) # simple plots spectro(tico,f=22050,wl=512) spectro(tico,f=22050,wl=512,osc=TRUE) spectro(tico,f=22050,wl=512,scale=FALSE) spectro(tico,f=22050,wl=512,osc=TRUE, scale=FALSE) # manipulating wl op<-par(mfrow=c(2,2)) spectro(tico,f=22050,wl=256,scale=FALSE) title("wl = 256") spectro(tico,f=22050,wl=512,scale=FALSE) title("wl = 512") spectro(tico,f=22050,wl=1024,scale=FALSE) title("wl = 1024") spectro(tico,f=22050,wl=4096,scale=FALSE) title("wl = 4096") par(op) # manipulating ovlp op<-par(mfrow=c(2,1)) spectro(alauda,f=22050,wl=512,scale=FALSE) title("ovlp = 0") spectro(alauda,f=22050,wl=512,ovlp=95,scale=FALSE) title("ovlp = 95") par(op) # a full plot pellu2<-cutw(pellucens,f=22050,from=1,to=nrow(pellucens)/22050,plot=FALSE) spectro(pellu2,f=22050,wl=512,ovlp=85,zp=16,osc=TRUE, cont=TRUE,contlevels=seq(-30,0,20),colcont="red", lwd=1.5,lty=2,palette=rev.terrain.colors) # black and white spectrogram spectro(pellu2,f=22050,wl=512,ovlp=85,zp=16, palette=rev.gray.colors) # colour modifications spectro(pellu2,f=22050,wl=512,ovlp=85,zp=16, palette=rev.cm.colors,osc=TRUE,colwave="orchid1") op<-par(bg="black",col="white") spectro(pellu2,f=22050,wl=512,ovlp=85,zp=16,osc=TRUE,palette=rev.heat.colors, colgrid="white", colwave="white",colaxis="white",collab="white", colline="white") par(op)