www.gusucode.com > matlab 案例源码 matlab代码程序 > matlab/ExpansionWithComplexRootsAndEqualDegOfNumAndDenExample.m
%% Expansion with Complex Roots and Equal Degree of Numerator and Denominator % If the degree of the numerator is equal to the degree of the denominator, % the output |k| can be nonzero. % % Find the partial fraction expansion of a ratio of two polynomials % _F_(_s_) with complex roots and equal degree of numerator and % denominator, where _F_(_s_) is % % $$F(s) = \frac{b(s)}{a(s)} = \frac{2s^3+s^2}{s^3+s+1}.$$ % % Copyright 2015 The MathWorks, Inc. b = [2 1 0 0]; a = [1 0 1 1]; [r,p,k] = residue(b,a) %% % |residue| returns the complex roots and poles, and a constant term % in |k|, representing the partial fraction expansion % % $$F(s) = \frac{b(s)}{a(s)} = \frac{2s^3+s^2}{s^3+s^2+1} = % \frac{0.5354+1.0390i}{s-(0.3412+1.1615i)} + \frac{0.5354-1.0390i}{s-(0.3412-1.1615i)} + % \frac{-0.0708}{s+0.6823}+2.$$