dynspec: 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, wl = 512, wn = "hanning", zp = 0,
ovlp = 0, fftw = FALSE, norm = FALSE, dB = NULL,  dBref = NULL, plot = TRUE,
title = TRUE, osc = FALSE, 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.

sampling frequency of wave (in Hz). Does not need to be specified if embedded in wave.

if at is not null, length of the window for the analysis (even number of points, by defaults = 512).

window name, see ftwindow (by default "hanning").

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.

a character string specifying the type dB to return: "max0" for a maximum dB value at 0, "A", "B", "C" and "D" 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).

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).

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

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).

Value

This function returns a list of three items:
timea numeric vector corresponding to the time axis.
freqa numeric vector corresponding to the frequency axis.
ampa numeric matrix corresponding to the amplitude values. Each column is a Fourier transform of length wl/2.

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.

Examples

Run this code

data(sheep)
require(rpanel)
dynspec(sheep,f=8000,wl=1024,ovlp=50,osc=TRUE)

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