stft(X, win=min(80,floor(length(X)/10)), inc=min(24, floor(length(X)/30)), coef=64, wtype="hanning")
X
| The vector from which the stft is computed. |
win
| Length of the window. For long vectors the default window size is 80, for short vectors the window size is chosen so that 10 windows fit in the vector. |
inc
| Increment by which the window is shifted. For long vectors the default increment is 24, for short vectors the increment is chosen so that 30 increments fit in the vector. |
coef
| Number of Fourier coefficients |
wtype
| Type of window used |
X
.
First, time-slices of length win
are
extracted from the vector. The shift of one time-slice to the next one is
given by inc
. The values of these time-slices are smoothed by
mulitplying them with a window function specified in wtype
. For
the thus obtained windows, the Fast Fourier Transform is computed.
values
|
A matrix containing the results of the stft. Each row of
the matrix contains the coef Fourier coefficients of one
window.
|
windowsize
|
The value of the parameter win
|
increment
|
The value of the parameter inc
|
windowtype
|
The value of the parameter wtype
|
x<-rnorm(500) y<-stft(x) plot(y)