eatfjs3.m

为配套王能超版本数值分析简明教程编写,方便学生教师演示!

function X=eAtfjs3(A,t)
[n,m]=size(A);
syms x
f=det(A-x*eye(n));
a=solve(f);
Q=eye(n);
syms s
r=exp(a(1)*t);
S=r*Q;
for i=2:n;
    r1=inline(r);
    r=int(exp(a(i)*(t-s))*r1(s),s,0,t);
    Q=(A-a(i-1)*eye(n))*Q;
    S=S+r*Q;
end
X=S;