%X(s)=B(s)/A(s)
%求極點(diǎn)
A=[1 4 6 4];%store the coefficients of A(s),按降冪排列
p=roots(A)%求X(s)的極點(diǎn)poles
%用留數(shù)定理求laplace反變換
num=[1 2];
den=[1 4 3 0];
[r,p]=residue(num,den)