tensile_spring的专栏

function [X]=dtft(x,n,w) X=x*exp(-j*n'*w) dtft的函数的编写

练习题1 n=-12:12 x11=((n>=-2)-(n>=2)) x12=2.^n x1=x11.*x12 subplot(3,1,1);stem(n,x1,'.') x21=(n==-4) x22=(n==4) x2=-x21+x22 subplot(3,1,2);stem(n,x2,'.') title('x1(n)=2n') x3=cos(0.3*pi*n) subplot(3,1,3