wf {seewave}R Documentation

Waterfall display

Description

This function returns a waterfall display of a short-term Fourier transform or of any matrix.

Usage

wf(wave, f = NULL, wl = 512, zp = 0, ovlp = 0, wn = "hanning", 
x = NULL, hoff = 1, voff = 1, col = heat.colors,
xlab = "Frequency (kHz)", ylab = "Amplitude (dB)", xaxis = TRUE, yaxis =
TRUE, density = NULL, border = NULL, lines = FALSE, ...)

Arguments

wave a vector, a matrix (first column), an object of class ts, Sample (left channel), or Wave (left channel).
f sampling frequency of wave (in Hz). Does not need to be specified if wave is an object of class ts, Sample, or Wave.
wl window length for the analysis (even number of points). (by default = 512)
zp zero-padding (even number of points), see Details.
ovlp overlap between two successive windows (in %).
wn window name, see ftwindow (by default "hanning").
x a matrix if wave is not provided.
hoff horizontal 'offset' which shifts actual x-values slightly per row for visibility. Fractional parts will be removed.
voff vertical 'offset' which separates traces.
col a color or a color palette function to be used to assign colors in the plot
xlab title of the frequency x-axis.
ylab title of the amplitude y-axis.
xaxis a logical, if TRUE adds the frequency x-axis according to f.
yaxis a logical, if TRUE adds the amplitude y-axis according.
density argument of polygon: the density of shading lines, in lines per inch. The default value of 'NULL' means that no shading lines are drawn. A zero value of 'density' means no shading nor filling whereas negative values (and 'NA') suppress shading (and so allow color filling).
border argument of polygon: the color to draw the border. The default, 'NULL', means to use 'par("fg")'. Use 'border = NA' to omit borders.
lines a logical, if TRUE plots lines instead of surfaces (polygons).
... other graphical arguments to passed to plot

Details

Data input can be either a time wave (wave) or a matrix (x). In that case, if xaxis is set to TRUE the x-axis will follow the row index. To change it, turn xaxis to FALSE and use axis afterwards. See examples.

Note

The function is well adapted to display short-term Fourier transform. However, any matrix can be called using the argument x instead of wave.

Author(s)

Carl G. Witthoft and Jerome Sueur sueur@mnhn.fr

See Also

spectro, spectro3D, dynspec

Examples

data(tico)
wf(tico,f=22050)
# changing the display parameters
jet.colors <- colorRampPalette(c("blue", "green"))
wf(tico,f=22050, hoff=0, voff=2, col=jet.colors, border = NA)
# matrix input instead of a time wave and transparent lines display
m <- numeric()
for(i in seq(-pi,pi,len=40)) {m <- cbind(m,10*(sin(seq(0,2*pi,len=100)+i)))}
wf(x=m, lines=TRUE, col="#0000FF50",xlab="Time", ylab="Amplitude",
main="waterfall display")

[Package seewave version 1.5.4 Index]