Error with Fmincon nonlinear constraint

Question

Brian Noiret 2020-3-27

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/513357-error-with-fmincon-nonlinear-constraint

评论： Alan Weiss 2020-3-30

采纳的回答： Alan Weiss

在 MATLAB Online 中打开

Hi! I encounter a problem trying to use fmincon to solve a nonlinear equation system. The message error:

Error in Untitled (line 12)

F=@(n) [n(1) + n(2) + n(3) + n(4) + n(5) + n(6) + n(7) + n(8) + w - n(9);...

Error in fmincon (line 639)

[ctmp,ceqtmp] = feval(confcn{3},X,varargin{:});

Error in Untitled (line 28)

n=fmincon(@(x)0,x0,[],[],[],[],lb,ub,[[],F],opts);

Caused by:

Failure in initial nonlinear constraint function evaluation. FMINCON cannot continue.

Hereunder you can find a simplified version of my code that returns that error as well. This being the first time I use fmincon, I assume I made a basic syntax error, can anyone help me with this?

nIt = 1;
for ii=1:nIt
% K01 = ;
% K02 = ;
% K03 = ;
% K04 = ;
% 
% a = ; b = ; c = ;
% u = ; v = ; w = ; x = ; y = ; z = ;
F=@(n) [n(1) + n(2) + n(3) + n(4) + n(5) + n(6) + n(7) + n(8) + w - n(9);...
        1 - (n(3) * n(2) / (n(1) * n(4)))/K01;...
        1 - (n(7) / (n(8) * n(6)) * n(9) / u)/K02;...
        1 - (n(2) / (n(5) * n(6)) * n(9) / u)/K03;...
        1 - (n(6)^2 / n(4) * u / n(9))/K04;...
        a*x - n(1) - n(3);...
        4*(c) + a*y - 2*n(2) - 2*n(4) - n(5) - n(6) - n(7);...
        c - n(7) - n(8);...
        4*(c) + a*z - 2*n(1) - n(2) - n(3) - n(5) - 3*v];
    
    
lb = zeros(1,9); % Lower bound constraint
ub = 10*ones(1,9); %upper bound constraints
rng default % Reproducible initial point 
x0 = exprnd(1,9); %initial values
opts = optimoptions(@fmincon,'Algorithm','interior-point','Display','off');
n=fmincon(@(x)0,x0,[],[],[],[],lb,ub,[[],F],opts);
end