ex030900.m

来自「主要是介绍DSP算法在matlab中的实现」· M 代码 · 共 43 行

n = 0:100; x = cos(pi*n/2);

k = -100:100; w = (pi/100)*k;        % frequency between -pi and +pi

X = x * (exp(-j*pi/100)).^(n'*k);    % DTFT of x

%

y = exp(j*pi*n/4).*x;                % signal multiplied by exp(j*pi*n/4)

Y = y * (exp(-j*pi/100)).^(n'*k);    % DTFT of y

% Graphical verification

subplot(1,1,1)

subplot(2,2,1); plot(w/pi,abs(X)); grid; axis([-1,1,0,60])

xlabel('frequency in pi units'); ylabel('|X|')

title('Magnitude of X')

subplot(2,2,2); plot(w/pi,angle(X)/pi); grid; axis([-1,1,-1,1])

xlabel('frequency in pi units'); ylabel('radiands/pi')

title('Angle of X')

subplot(2,2,3); plot(w/pi,abs(Y)); grid; axis([-1,1,0,60])

xlabel('frequency in pi units'); ylabel('|Y|')

title('Magnitude of Y')

subplot(2,2,4); plot(w/pi,angle(Y)/pi); grid; axis([-1,1,-1,1])

xlabel('frequency in pi units'); ylabel('radians/pi')

title('Angle of Y')