还有用过fsolve函数求解:
建立myfun.m文件:
function F = myfun(x)
F = [0.9*2.7183^(x(1)*(38-x(2))^x(3))-1;
2.7183^(x(1)*(402-x(2))^x(3))-2;
2.7183^(x(1)*(740-x(2))^x(3))-10];
end
然后在命令窗口输入:
>> [x,fval]=fsolve(@myfun,[0,50,1]);
x(1)
x(2)
x(3)
Error using feval
Undefined function 'myfun' for input arguments of type 'double'.
Error in fsolve (line 241)
fuser = feval(funfcn{3},x,varargin{:});
Caused by:
Failure in initial user-supplied objective function evaluation. FSOLVE cannot
continue.
我用solve函数求解如下:
syms x y z;
f1=0.9*2.7183^(x*(38-y)^z)-1;
f2=2.7183^(x*(402-y)^z)-2;
f3=2.7183^(x*(740-y)^z)-10;
[x,y,z]=solve(f1==0,f2==0,f3==0)
但是计算结果却是这样的:
Warning: Explicit solution could not be found.
> In solve at 169
x =
[ empty sym ]
y =
[]
z =
[]
菜鸟求解答!!!!~~~~
还有用过fsolve函数求解:
建立myfun.m文件:
function F = myfun(x)
F = [0.9*2.7183^(x(1)*(38-x(2))^x(3))-1;
2.7183^(x(1)*(402-x(2))^x(3))-2;
2.7183^(x(1)*(740-x(2))^x(3))-10];
end
然后在命令窗口输入:
>> [x,fval]=fsolve(@myfun,[0,50,1]);
x(1)
x(2)
x(3)
Error using feval
Undefined function 'myfun' for input arguments of type 'double'.
Error in fsolve (line 241)
fuser = feval(funfcn{3},x,varargin{:});
Caused by:
Failure in initial user-supplied objective function evaluation. FSOLVE cannot
continue.
结果不懂什么原因啊,还有初值[0,50,1]我不知道对不对,初值具体应该怎么确定啊?
求各路高手解答,菜鸟一个,对matlab一窍不通,求大神们帮帮忙~~~,
有没有人解答解答啊,泪花ing~~~
我已经知道自己错误的原因在哪了,M-文件保存的路径不对,我是自定义保存的。然后再请教一个问题,初值x0的确定对方程组的解的结果影响非常大,要怎样确定初值或是什么方法逐渐找到初值,使得结果误差在所需范围之内?