Functions > Signal Processing > Joint Time-Frequency Analysis > Short-time Fourier Transform
  
Short-time Fourier Transform
• stft(v, [n], [s], [w])—Returns a matrix containing the short time Fourier transform of signal v. The stft function computes n frequencies, every s samples, and tapers each block with window (or window type) w.
Arguments
• v is a vector of complex-valued data.
• n (optional) is an integer, the number of transform frequencies. If n is omitted, then it defaults to 64.
• s (optional) is an integer, the number of samples to skip between successive computations. If s is omitted, then it defaults to n/2.
• w (optional) is an integer representing a windowing function index. A rectangular window is used if w is 0 or not specified.
Alternatively, w is a vector containing the coefficients of an FIR filter whose length is not longer than n.
The following table shows values for w and the windows they correspond to:
Value of w
Window
0
current default window
1
rectangular (default)
2
tapered rectangular
3
triangular
4
Hanning
5
Hamming
6
Blackman
7
Nuttall