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t=[t1,t2,t3];
f=[zeros(1,length(t1)),ones(1,length(t2)),zeros(1,length(t3))]; m0=5;
f1=[zeros(1,m0),f];f2=f1(1:length(f)) w=-2*pi:0.1:2*pi; F=f*exp(-j*t'*w)*dt;
subplot(2,2,1);plot(w,abs(F));grid; subplot(2,2,2);plot(w,angle(F));grid; F2=f2*exp(-j*t'*w)*dt;
subplot(2,2,3);plot(w,abs(F2));grid; subplot(2,2,4);plot(w,angle(F2));grid; ·ÂÕæ½á¹û:
19
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Command Window
dt=0.1; N=500; door__width=10; tao=door__width/2; t1=-(N-1):dt:-tao+1; t2=-tao:dt:tao; t3=tao-1:dt:N-1; t=[t1,t2,t3];
f=[zeros(1,length(t1)),ones(1,length(t2)),zeros(1,length(t3))]; w1=0.5*pi;
f2=f.*exp(-j*w1*t); w=-2*pi:0.1:2*pi; F=f*exp(-j*t'*w)*dt;
subplot(2,2,1);plot(w,abs(F));grid; subplot(2,2,2);plot(w,angle(F));grid; F2=f2*exp(-j*t'*w)*dt;
subplot(2,2,3);plot(w,abs(F2));grid; subplot(2,2,4);plot(w,angle(F2));grid; ·ÂÕæ½á¹û£º
20
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(3)»³ög£¨*g£¨µÄƵÆ×ͼ£¬Ñé֤ʱÓò¾í»ý¶¨Àí¡£ ?t£©?t£©Command Window
dt=0.1;N=50; door__width=8; tao=door__width/2; t1=-(N-1):dt:-tao+dt; t2=-tao:dt:tao; t3=tao-dt:dt:N-1; t=[t1,t2,t3];
f=[zeros(1,length(t1)),ones(1,length(t2)),zeros(1,length(t3))]; [k,f2]=myconv(f,f,t,t,dt) subplot(2,2,1);stairs(t,f); subplot(2,2,2);plot(k,f2); w=-2*pi:0.1:2*pi;
21
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F=f*exp(-j*t'*w)*dt;
subplot(2,2,3);plot(w,abs(F));grid; F2=f2*exp(-j*t'*w)*dt;
subplot(2,2,4);plot(w,abs(F2));grid; µÃµ½²¨ÐÎÈçÏÂͼËùʾ£º
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Command Window
dt=0.03;N=10; door__width=10; tao=door__width/2; t1=-(N-1):dt:-tao-dt; t2=-tao:dt:tao; t3=tao-dt:dt:N-1; t=[t1,t2,t3];
22
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f=[zeros(1,length(t1)),ones(1,length(t2)),zeros(1,length(t3))]; subplot(2,2,1);stairs(t,f);grid;title('Ãź¯Êý²¨ÐÎ'); f2=10*sin(5*t)./(5*t);
subplot(2,2,2); plot(t,f2);grid;title('Saº¯Êý²¨ÐÎ'); w=-2*pi:0.1:2*pi; F=f*exp(-j*t'*w)*dt;
subplot(2,2,3);plot(w,real(F));grid;title('Ãź¯ÊýƵÆ×'); F2=f2*exp(-j*t'*w)*dt;
subplot(2,2,4);plot(w,real(F2));grid;title('Saº¯ÊýƵÆ×'); ·ÂÕæ½á¹û£º
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Command Window
dt=0.01;N=20; door_width=5; tao=door_width/2;
23