《DSP using MATLAB》示例Example4.10

上代码：

b = [1, 0.4*sqrt(2)]; a = [1, -0.8*sqrt(2), 0.64];               %  compute the polynomials coefficients given its roots

[R,p,C] = residuez(b,a)

Mp = (abs(p))'           % pole magnitudes

Ap = (angle(p))'/pi      % pole angles in pi units

[delta, n] = impseq(0, 0, 7); x_check = filter(b, a, delta);       % check sequence

x_answer = ((0.8).^n) .* (cos(pi*n/4) + 2*sin(pi*n/4));            % answer sequence

%[b,a] = residuez(R,p,c)

　　运行结果：

      脉冲序列只取[0,7]，故x_check和x_answer仅前8个元素，上图可知都相同。