箫风禅月
2011-11-29, 16:54
方程为：（求x1,x2,x3，即a，b，c）
第一个：((2*a+3*b+c)^2*(a+b)*(1-c))/((1-a-b)*(2-0.5*a)^0.5*(4+1.5*a+2*b)^1.5)-3.46e11;
第二个：((2*a+3*b+c)^3*(a+b)*(1-c))/((1-a-b)*(1-b-c)^0.5*(4+1.5*a+2*b)^2)-0.966;
第三个：((2*a+3*b+c)*(a+b)*c)/((a+b)*(1-c)*(1-b-c))-1.176;
我编程为：
function f=my1(x)
a=x(1);
b=x(2);
c=x(3);
f(1)=((2*a+3*b+c)^2*(a+b)*(1-c))/((1-a-b)*(2-0.5*a)^0.5*(4+1.5*a+2*b)^1.5)-3.46e11;
f(2)=((2*a+3*b+c)^3*(a+b)*(1-c))/((1-a-b)*(1-b-c)^0.5*(4+1.5*a+2*b)^2)-0.966;
f(3)=((2*a+3*b+c)*(a+b)*c)/((a+b)*(1-c)*(1-b-c))-1.176;
导入matlab中：
>>x0=[3.9 0.5 0];
>> f=fsolve('my1',x0)
出现：
No solution found.
fsolve stopped because the last step was ineffective. However, the vector of function
values is not near zero, as measured by the default value of the function tolerance.
<stopping criteria details>
f =
3.0832 -1.7871 0.6274
请问这是怎么回事呀？怎么才能求出结果呢？本人菜鸟，请高手帮忙，感激不尽！
第一个：((2*a+3*b+c)^2*(a+b)*(1-c))/((1-a-b)*(2-0.5*a)^0.5*(4+1.5*a+2*b)^1.5)-3.46e11;
第二个：((2*a+3*b+c)^3*(a+b)*(1-c))/((1-a-b)*(1-b-c)^0.5*(4+1.5*a+2*b)^2)-0.966;
第三个：((2*a+3*b+c)*(a+b)*c)/((a+b)*(1-c)*(1-b-c))-1.176;
我编程为：
function f=my1(x)
a=x(1);
b=x(2);
c=x(3);
f(1)=((2*a+3*b+c)^2*(a+b)*(1-c))/((1-a-b)*(2-0.5*a)^0.5*(4+1.5*a+2*b)^1.5)-3.46e11;
f(2)=((2*a+3*b+c)^3*(a+b)*(1-c))/((1-a-b)*(1-b-c)^0.5*(4+1.5*a+2*b)^2)-0.966;
f(3)=((2*a+3*b+c)*(a+b)*c)/((a+b)*(1-c)*(1-b-c))-1.176;
导入matlab中：
>>x0=[3.9 0.5 0];
>> f=fsolve('my1',x0)
出现：
No solution found.
fsolve stopped because the last step was ineffective. However, the vector of function
values is not near zero, as measured by the default value of the function tolerance.
<stopping criteria details>
f =
3.0832 -1.7871 0.6274
请问这是怎么回事呀？怎么才能求出结果呢？本人菜鸟，请高手帮忙，感激不尽！