15.2.24 Riemann window function:
riemann_window
The
riemann_window
command finds a Riemann window of a sequence.
riemann_window
takes one mandatory argument and one optional argument:
v
, a real vector with length
n
.
Optionally, an interval
n
0
..
n
1
(by default 0..(
n
−1)).
riemann_window(
v
⟨,
n
1
..
n
2
⟩
)
returns the elementwise product of [
v
n
1
,…,
v
n
2
] and the vector
w
of length
N
=
n
2
−
n
1
+1 defined by
w
k
=
⎧
⎪
⎪
⎪
⎨
⎪
⎪
⎪
⎩
1,
k
=
N
−1
2
,
sin(π
x
k
)
π
x
k
,
otherwise,
where
x
k
=2
k
/
N
−1−1 for
k
=0,1,…,
N
−1.
Example.
Input:
L0:=randvector(1000,0..1):;
scatterplot(L0);
Output:
Input:
L:=riemann_window(L0):;
scatterplot(L);
Output:
