### 21.5.1 Bartlett-Hann window

The bartlett_hann_window command applies the Bartlett-Hahn window to a sequence or its segment.

- bartlett_hann_window takes one mandatory argument and two optional arguments:
  - v, a real vector with length n.
  - Optionally, m, N, a sequence of two integers (by default, m=0 and N=n).
- bartlett_hann_window returns the elementwise product of [vm,vm+1,…,vm+N−1] and the vector w of length N 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

listplot(bartlett_hann_window([1$1000]))