15.2.14  Blackman-Harris window function: blackman_harris_window

The blackman_harris_window command finds a Blackman-Harris window of a sequence.

• blackman_harris_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)).
• blackman_harris_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 cos

  ⎛ ⎜ ⎜ ⎝

  2 k π N−1

  ⎞ ⎟ ⎟ ⎠

  +a2 cos

  ⎛ ⎜ ⎜ ⎝

  4 k π N−1

  ⎞ ⎟ ⎟ ⎠

  −a3 cos

  ⎛ ⎜ ⎜ ⎝

  6 k π N−1

  ⎞ ⎟ ⎟ ⎠

  for k=0,1,…,N−1, where a₀=0.35875, a₁=0.48829, a₂=0.14128 and a₃=0.01168.

Example.
Input:

Output:

Input:

Output: