expfj.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 s=expfj(A)
syms x t
[n,m]=size(A);
y=eig(A);
z=zeros(1,n);
for i=1:n;
    for j=1:n;
        for k=i-1:-1:1;
            if y(k)==y(i);
               z(i)=z(i)+1;
           end
       end
       c=diff(x^(j+z(i)),x,z(i));
       c=inline(c);
       B(i,j)=c(y(i));
       a=diff(exp(x*t));
       a=inline(a);
       b(i)=a(y(i),t);
   end
end
b=b';
x1=gaussxqf(B,b);
s=0;
for i=1:n;
    s=s+x1(i)*A^(i-1);
end