plot(t,f)
axis([-8,10,-6,6])
2.·Ö±ðÓÃMATLAB±íʾ²¢»æ³öÏÂÁÐÀëɢʱ¼äÐźŵIJ¨ÐΣº ¢Æ f(t)?k??(k)??(k?8)? k1=-5;k2=10;k0=0;k3=8
k=k1:-k0-1;kk=-k0:k3;kkk=k3+1:k2;
n=length(k); nn=length(kk); nnn=length(kkk); u=zeros(1,n); uu=ones(1,nn); uuu=zeros(1,nnn); stem(k,u,'filled') hold on
stem(kk,kk,'filled') hold on
stem(kkk,uuu,'filled') hold off
axis([k1,k2,0,10])
¢È f(k)??(?k?2)
k1=-10;k2=10;k0=2;
k=k1:-k0;kk=-k0+1:k2;
n=length(k); nn=length(kk); u=ones(1,n); uu=zeros(1,nn); stem(k,u,'filled') hold on
stem(kk,uu,'filled') hold off
axis([k1,k2,0,2])
3.ÒÑÖªÐźÅf(t)µÄ²¨ÐÎÈçÏÂͼËùʾ£¬ÊÔÓÃMATLAB»æ³öÂú×ãÏÂÁÐÒªÇóµÄÐźŲ¨ÐΡ£
¢Æ f(t?2) t=-3:0.01:7;
t1=2;
u1=stepfun(t,t1); t2=3;
u2=stepfun(t,t2); t3=4;
u3=stepfun(t,t3); g=2*u1-u2-u3; plot(t,g) axis([-3,7,-2,4])
¢È f(0.5t?1)
t=-5:0.01:5; t1=0-1;
u1=stepfun(t,t1); t2=1/2-1; u2=stepfun(t,t2); t3=1-1;
u3=stepfun(t,t3); g=2*u1-u2-u3; plot(t,g) axis([-5,5,-2,4])
4.ÒÑÖªÁ½ÐźÅf1(t)??(t?1)??(t)£¬f2(t)??(t)??(t?1)£¬Çó¾í»ý»ý·Ö
g(t)?f1(t)?f2(t)£¬²¢ÓëÀýÌâ±È½Ï¡£
t1=-1:0.01:0;t2=0:0.01:1; t3=-1:0.01:1; f1=ones(size(t1)); f2=ones(size(t2)); g=conv(f1,f2); plot(t3,g);
?te?t?(t)5.ÒÑÖªÁ½ÐźÅf1(t)?t?(t)£¬f2(t)??t?eg(t)?f1(t)?f2(t)¡£
t?0t?0 £¬Çó¾í»ý»ý·Ö
t1=0:0.01:5;t2=-5:0.01:5;
t3=-5:0.01:10; f1=t1;
f2=exp(t2).*(t2<0)+t2.*exp(-t2).*(t2>=0); g=conv(f1,f2); plot(t3,g);
6.ÒÑÖªf1(k)??1,1,1,2?,f2(k)??1,2,3,4,5?£¬ÇóÁ½ÐòÁеľí»ýºÍf1=[1,1,2]; f2=[1,2,3,4,5]; g=conv(f1,f2); N=length(g); stem(0:N-1,g);
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