[交流] MATLAB问题 程序怎么会出错？Error: Missing variable or function. 怎么修改？

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function dx=myfun(t,x)

dx(1)-x(3)+x(2)-x(4)*x(2)+2*x(5)*x(2)+x(2)*x(2)+x(5)+e+f+g=0;
dx(2)-x(1)+x(3)-x(4)*x(2)+x(2)*x(2)+x(5)*x(5)+x(5)*x(2)+e*f+g=0;
dx(3)-x(2)+x(1)-x(5)*x(1)+x(4)*x(3)-x(3)-x(4)-e*g-f=0;
x(4)*x(5)+x(2)*x(3)+e*f+e*g-x(6)=0;
dx(4)-x(5)*a-x(3)*x(1)-x(3)-e*f*g*x(6)=0;
dx(5)-x(4)*a-x(2)*x(1)+e*f*x(1)+x(2)*x(2)*x(5)+x(2)*x(5)*x(5)+e*f+f*g=0;

a=a1+a2;
e=e1+e2;
f=f1+f2;
g=g1+g2;

a1=1;
a2=1;
e1=9;
e2=7;
f1=56;
f2=98;
g1=76;
g2=665;

dx=dx(:);
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然后，在Matlab下面输入： 
clear all
clc
syms a e f g a1 a2 e1 e2 f1 f2 g1 g2
x0=[1,1,1,1,1,1];
t0=0:0.1:2;
[t,x]=solver('myfun',[0,10],x0);  %ode45会自动调整步长
plot(t,x) 
legend('x(1)','x(2)','x(3)','x(4)','x(5)','x(6)')