matlab课后作业 北交大 钱满义

(3) k=-50:50;

>> xk=10*(0.5.^k).*[zeros(1,50),ones(1,51)]; >> stem(k,xk)

109876543210-50-40-30-20-1001020304050

(4) k=-50:50;

>> xk=[zeros(1,48),ones(1,7),zeros(1,46)]; >> stem(k,xk)

10.90.80.70.60.50.40.30.20.10-50-40-30-20-1001020304050

(5) k=-50:50;

uk=k.*[zeros(1,50),ones(1,51)]; stem(k,uk)

50454035302520151050-50-40-30-20-1001020304050

(6)

k=-50:50;

>> xk=5.*(0.8.^k).*cos(0.9*pi.*k).*[ones(1,101)]; >> stem(k,xk)

3x 105210-1-2-3-4-50-40-30-20-1001020304050

M2-6 W=0.1pi k=-50:50; >> w=0.1*pi; >> xk=sin(w.*k); >> stem(k,xk);

10.80.60.40.20-0.2-0.4-0.6-0.8-1-50-40-30-20-1001020304050

W=0.5pi k=-50:50; >> w=0.5*pi; >> xk=sin(w.*k); >> stem(k,xk);