date=load('D:\plog.txt');
x=date;
for t=2:482
    y(t)=x(t-1,:);
end
s(1)=0;
y(1)=0;
for t=2:482
    s(t)=y(t-1)-c-a*y(t-1)-b*s(t-1);
end
d=g^(2);
f=1/(sqrt(2*pi*d))*exp{-s(t)^(2)/(2*d)};
h=cumprod(f);
L=log(h);
A=[a,b,c,d];
d1=diff(L,A);
fun=infine('d1');
[a,b,c,d]=ode23(fun,0.00,0.00,0.00,1);
The following error occurred converting from sym to double:
Error using mupadmex
Error in MuPAD command: DOUBLE cannot convert the input expression into a double array.

If the input expression contains a symbolic variable, use the VPA function instead.


请高手帮忙分析一下这是什么原因？