4楼: Originally posted by 月只蓝 at 2013-10-15 09:04:27
没什么大问题，就是待求解方程没写对。以下所有程序复制进一个m文件运行即可。你可以检查一下fx(1)写得对不对。
function solve_nonlEqs
format long
x0=;
x=fsolve(@mnsi,x0)
fval=mnsi(x)

function fx=mn ...

2楼: Originally posted by 月只蓝 at 2013-10-14 20:52:26
x在哪里呢?

function solve_nonlEqs
format long
x0=[0.0350 0.16565];
x=fsolve(@mnsi,x0)
fval=mnsi(x)

function fx=mnsi(x)
T=1700;
a=[-45584.1,-39280.9,-10069.8,34484.37];
b=[28.50974,6.881164,2.113303,17.83834];
c=[0.5;0.5];
k=zeros(1,4);
for i=1:1:4;
k(i)=exp(a(i)/T+b(i));
end
fx(1)=c(1)*x(1)- c(2)*x(2)+(3* c(1)- c(2))*k(1)*((x(1)^3)* x(2))+ (5* c(1)- 3*c(2))*k(2)*(x(1)^5)* x(2)^3+(c(1)- c(2))*k(3)*(x(1)* x(2)+ (11* c(1)- 19*c(2))*k(4)*(x(1)^11)* (x(2))^19);
fx(2)=x(1)+x(2)+ k(1)*((x(1)^3)* x(2)+ k(2)*(x(1)^5)* (x(2))^3)+ k(3)*(x(1)* x(2)+ k(4)*(x(1)^11)* (x(2))^19);