This variable is set to one of the following strings, which will determine the type of windowing used for the Fourier transform in the spec and fft command. If not set, the default is hanning.

• none
  No windowing
• rectangular
  Rectangular window
• bartlet
  Bartlett (also triangle) window
• blackman
  Blackman window
• hanning
  Hanning (also hann or cosine) window
• hamming
  Hamming window
• gaussian
  Gaussian window
• flattop
  Flat top window

Figure 17.1: Spec and FFT window functions (Gaussian order = 4)