four.m

matlab的一些基础程序

%d) x(n)={...,5,4,3,2,1,5,4,3,2,1,...}; -10<=n<=9
%
l4=figure;
n=[-10:9];
x=[5,4,3,2,1];
xtilde=x'*ones(1,4);
xtilde=(xtilde(:))';
stem(n,xtilde);title('Sequence in Example 3.1d');
xlabel('n'); ylabel('xtilde(n)');axis([-10,9,-1,6]);