cos.m

一个ＤＣＴ函数的程序

t=0:0.01:1;
N=1;
x=cos(N*pi*t);
p=x+x.^2;
q=abs(p)*0.5;
y1=20*log10(q); 
 
N=2;
x=cos(N*pi*t);
p=x+x.^2;
q=abs(p)*0.5;
y2=20*log10(q); 
 
N=4;
x=cos(N*pi*t);
p=x+x.^2;
q=abs(p)*0.5;
y3=20*log10(q); 
 
N=8;
x=cos(N*pi*t);
p=x+x.^2;
q=abs(p)*0.5;
y4=20*log10(q); 
plot(t,y1,'c.-',t,y2,'b.-',t,y3,'g.:',t,y4,'r.-.');
axis([0,1,-60,0])
xlabel('w/pi')
ylabel('Gain(dB)')
grid on