two.m

matlab的一些基础程序

%b) x(n)=n[u(n) - u(n -10)] + 10*exp(-0.3(n-10))(u(n-10)-u(n-20));
%    0<=n<=20
%
switch  b 
    case  'ab'
        clc,clf 
       subplot('Position',    [0.1 0.3 0.8 0.6])
m2=uicontrol(gcf,'style','pushbutton','string','上一题','fontsize',18,'units','normalized','position',...
    [0.1 0.1 0.2 0.1],'foregroundcolor','r','backgroundcolor','b','callback','one');
m3=uicontrol(gcf,'style','pushbutton','string','回目录','fontsize',18,'units','normalized','position',...
    [0.4 0.1 0.2 0.1],'foregroundcolor','r','backgroundcolor','b','callback','abc');
m3=uicontrol(gcf,'style','pushbutton','string','下一题','fontsize',18,'units','normalized','position',...
    [0.7 0.1 0.2 0.1],'foregroundcolor','r','backgroundcolor','b','callback','three');
        
    case  '1'    
      figure;
end
n=[0:20];
x1=n.*(stepseq(0,0,20) -stepseq(10,0,20));
x2=10*exp(-0.3*(n-10)).*(stepseq(10,0,20) - stepseq(20,0,20));
x=x1+x2;
stem(n,x);title('Sequence in Example 3.1b');
xlabel('n'); ylabel('x(n)');axis([0,20,-1,11]);