R: Dynamic sliding spectrum

dynspec {seewave}

R Documentation

Dynamic sliding spectrum

Description

This function plots dynamically a sliding spectrum along a time wave. This basically corresponds to a short-term Fourier transform.

Usage

dynspec(wave, f, channel = 1, wl = 512, wn = "hanning", zp = 0,
ovlp = 0, fftw = FALSE, norm = FALSE, dB = NULL,  dBref = NULL, plot = TRUE,
title = TRUE, osc = FALSE, 
tlab = "Time (s)", flab = "Frequency (kHz)",
alab = "Amplitude", alim = NULL, flim = c(0, f/2000),
type = "l", from = NULL, to = NULL, envt = NULL,
msmooth = NULL, ksmooth = NULL, colspec = "black",
coltitle = "black", colbg = "white", colline = "black",
colaxis = "black", collab = "black", cexlab = 1,
fontlab = 1, colwave = "black",
coly0 = "lightgrey", colcursor = "red", bty = "l")

Arguments

`wave`	an R object.
`f`	sampling frequency of `wave` (in Hz). Does not need to be specified if embedded in `wave`.
`channel`	channel of the R object, by default left channel (1).
`wl`	if `at` is not null, length of the window for the analysis (even number of points, by defaults = 512).
`wn`	window name, see `ftwindow` (by default `"hanning"`).
`zp`	zero-padding (even number of points), see `Details`.
`ovlp`	overlap between two successive windows (in % ).
`fftw`	if `TRUE` calls the function `FFT` of the library `fftw`. See Notes of the `spectro`.
`norm`	logical, if `TRUE` compute a normalised sliding spectrum.
`dB`	a character string specifying the type dB to return: "max0" for a maximum dB value at 0, "A", "B", "C", "D", and "ITU" for common dB weights.
`dBref`	a dB reference value when `dB` is not `NULL`. `NULL` by default but should be set to 2*10e-5 for a 20 microPa reference (SPL).
`plot`	logical, if `TRUE` plots in an ew graphics device the successive spectra sliding along the time wave (by default `TRUE`).
`title`	logical, if `TRUE` adds a title with the time position of the current spectrum along the time wave.
`osc`	logical, if `TRUE` plots an oscillogram beneath the sliding spectrum with a cursor showing the position of the current spectrum (by default `FALSE`).
`tlab`	title of the time axis.
`flab`	title of the frequency axis.
`alab`	title of the amplitude axis.
`flim`	range of frequency axis.
`alim`	range of amplitude axis.
`type`	type of plot that should be drawn for the sliding spectrum. See `plot` for details (by default "l" for lines).
`from`	start mark where to compute the sliding spectrum (in s).
`to`	end mark where to compute the sliding spectrum (in s).
`envt`	the type of envelope to be plooted: either "abs" for absolute amplitude envelope or "hil" for Hilbert amplitude envelope. See `env`.
`msmooth`	when `env` is not `NULL`, a vector of length 2 to smooth the amplitude envelope with a mean sliding window. The first component is the window length (in number of points). The second component is the overlap between successive windows (in %). See `env`.
`ksmooth`	when `env` is not `NULL`, kernel smooth via `kernel`. See `env`.
`colspec`	colour of the sliding spectrum.
`coltitle`	if `title` is `TRUE`, colour of the title.
`colbg`	background colour.
`colline`	colour of axes line.
`colaxis`	colour of the axes.
`collab`	colour of axes title.
`cexlab`	character size for axes title.
`fontlab`	font for axes title.
`colwave`	colour of the oscillogram or of the envelope (only when `osc` is `TRUE`).
`coly0`	colour of the y=0 line (only when `osc` is `TRUE`).
`colcursor`	colour of oscillogram cursor (only when `osc` is `TRUE`).
`bty`	the type of box to be drawn around the oscillogram (only when `osc` is `TRUE`).

Details

Use the slider panel to move along the time wave.
Use the argument norm if you wish to have each spectrum normalised, i.e. with values between 0 and 1 or maximised to 0 dB when dB is TRUE.
The function requires the package rpanel that is based on the package tcltk.

Value

This function returns a list of three items:

`time`	a numeric vector corresponding to the time axis.
`freq`	a numeric vector corresponding to the frequency axis.
`amp`	a numeric matrix corresponding to the amplitude values. Each column is a Fourier transform of length `wl/2`.

Note

This function is very similar to a spectrogram. See the Details of spectro for some information regarding the short term Fourier transform.

Author(s)

Jerome Sueur and Caroline Simonis

Examples

## Not run: 
data(sheep)
require(rpanel)
dynspec(sheep,f=8000,wl=1024,ovlp=50,osc=TRUE)

## End(Not run)

[Package seewave version 2.1.6 Index]