Пример 2.2

n=[-2:10];%primer 2.2

x=[1:7,6:-1:1];

[x11,n11]=sigshift(x,n,5);

[x12,n12]=sigshift(x,n,-4);

[x1,n1]=sigadd(2*x11,n11,-3*x12,n12);

subplot(2,1,1);stem(n1,x1); title('Sequence 2.2a')

xlabel('n'); ylabel('x1(n)');

Ex1=sum(x1.*conj(x1))

[x21,n21]=sigfold(x,n);

[x21,n21]=sigshift(x21,n21,3);

[x22,n22]=sigshift(x,n,2);

[x22,n22]=sigmult(x,n,x22,n22);

[x2,n2]=sigadd(x21,n21,x22,n22);

subplot(2,1,2);stem(n2,x2); title('Sequence 2.2b')

xlabel('n'); ylabel('x2(n)');

Ex2=sum(x2.*conj(x2))

function [y,n]=sigshift(x,m,n0)

n=m+n0;

y=x;

function [y,n]=sigadd(x1,n1,x2,n2)

n=min(min(n1),min(n2)):max(max(n1),max(n2));

y1=zeros(1,length(n));

y2=y1;

y1(find((n>=min(n1))&(n<=max(n1))==1))=x1;

y2(find((n>=min(n2))&(n<=max(n2))==1))=x2;

y=y1+y2;

function [y,n]=sigfold(x,n)

y=fliplr(x);

n=-fliplr(n);

function [y,n]=sigfold(x,n)

y=fliplr(x);

n=-fliplr(n);

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Дата добавления: 2014-01-03