15.2.13  Bartlett-Hann window function: bartlett_hann_window

The bartlett_hann_window command finds a Bartlett-Hahn window of a sequence, which can be used to examine a short segment when analyzing a long.

• bartlett_hann_window takes one mandatory argument and one optional argument:
  • v, a real vector with length n.
  • Optionally, an interval n₀..n₁ (by default 0..(n−1)).
• bartlett_hann_window(v ⟨,n₁..n₂⟩) returns the elementwise product of [v_n1,…,v_n2] and the vector w of length N=n₂−n₁+1 defined by

  wk=a0+a1

  ⎪ ⎪ ⎪ ⎪

  k N−1

  −

  1 2

  ⎪ ⎪ ⎪ ⎪

  −a2 cos

  ⎛ ⎜ ⎜ ⎝

  2 k π N−1

  ⎞ ⎟ ⎟ ⎠

  for k=0,1,…,N−1 , where a₀=0.62 , a₁=0.48 and a₂=0.38 .

Example.
Input:

Output:

Input:

Output: