Short-time Fourier Transform |
stft(v, [n], [s], [w]) Returns a matrix containing the short time Fourier transform of a signal v; computes n frequencies, every s samples, and tapers each block with window (or window type) w.
w (optional) is an integer representing a windowing function. A rectangular window is used if w is omitted. The following table shows values for w and the windows they correspond to:
|
Value of w |
Window |
|
1 |
rectangular |
|
2 |
tapered rectangular |
|
3 |
triangular |
|
4 |
Hanning |
|
5 |
Hamming |
|
6 |
Blackman |
|
7 |
Nuttall |
Alternatively, w is a vector containing the coefficients of an FIR filter whose length is not longer than n.