summaryrefslogtreecommitdiff
path: root/40/CH8/EX8.24/Exa_8_24.sce
blob: 5ad54e146c76bd05ab8d1b548fc101feccee2c21 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
//The importance of Periodic extension
//(a)For M=3
x=[1 2 1];
XDFT=dft(x,-1)
w=exp(-%i*2*%pi/3);
for i=1:3
    for j=1:3
        WN(i,j)=w^((i-1)*(j-1));
    end
end
WI=WN';
xn=1/3*WI*XDFT
//The result is periodic with M=3 & 1 period equals x[n]
//(b)For M=4
y=[1 2 1 0];
YDFT=dft(y,-1)
w=exp(-%i*%pi/2);
for i=1:4
    for j=1:4
        WN(i,j)=w^((i-1)*(j-1));
    end
end
WI=WN';
yn=1/4*WI*YDFT