homework_one211.m

DSP信号处理

%题2-1-1
clc;clf;
%产生序列
%产生序列xn1，a=0.5, length=10
a1=0.5;  length1=10;   n1=0:1:length1-1;  xn1=a1.^n1;
%产生序列xn2，a=0.9, length=10
a2=0.9;  length2=10;   n2=0:1:length2-1;  xn2=a2.^n2;
%产生序列xn3，a=0.9, length=20
a3=0.9;  length3=20;   n3=0:1:length3-1;  xn3=a3.^n3;


%画序列
%画序列xn1，a=0.5, length=10
subplot(2,2,1);stem(n1,xn1,'full');axis([-5,length1+5,0,1]);
xlabel('n1');ylabel('x1(n)');  title('a=0.5, length=10 ');grid on;
%画序列xn2，a=0.9, length=10
subplot(2,2,2);stem(n2,xn2,'full');axis([-5,length2+5,0,1]);
xlabel('n2');ylabel('x2(n)');  title('a=0.9, length=10 ');grid on;
%画序列xn3，a=0.9, length=20
subplot(2,2,3);stem(n3,xn3,'full');axis([-5,length3+5,0,1]);
xlabel('n3');ylabel('x3(n)');  title('a=0.9, length=20 ');grid on;