Fsolve Error! Need help- Using Fsolve to solve system of non-linear equations.

Question

Collin Pautsch 2019-3-18

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/450627-fsolve-error-need-help-using-fsolve-to-solve-system-of-non-linear-equations

回答： Alex Sha 2019-4-22

% ***Function script
cpa=1.005;
cpg=1.148;
Qin=801.4;
t2=401;
t1=294.11;
p1=101.4;
p2=2.5*p1;
px=p2;
p3=.94*px;
p5=p1;
nreg=.8;
nc=.82;
nt=.85;
function F=myfun(x)
F=[x(10)-cpa*(t2-t1);
    x(10)-cpg*(x(2)-x(3));
    x(9)-cpg*(x(3)-x(4));
    Qin-cpg*(x(2)-x(1));
    nreg*(x(4)-t2)-(x(1)-t2);
    nc*(t1-t2)-(t1-x(5));
    nt*(x(2)-x(6))-(x(2)-x(3));
    nt*(x(3)-x(7))-(x(3)-x(4));
    x(5)-(2.5^(.28571429)*t1);
    x(6)-((x(8)/p3)^(.24981245)*x(2));
    x(7)-(p5/x(8))^(.24981245)*x(3)];
end
% ****Solver Code
x0=[440;1000;900;850;380;890;800;160;110;110];
options = optimoptions('fsolve','display','iter');
[x,fval]= fsolve(@project2,x0,options);

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Collin Pautsch 2019-3-18

I added them as attachments once I realized the pictures were unreadable.

Collin Pautsch 2019-3-18

I did now

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Answer 1

madhan ravi 2019-3-18

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/450627-fsolve-error-need-help-using-fsolve-to-solve-system-of-non-linear-equations#answer_365817

编辑：madhan ravi 2019-3-18

在 MATLAB Online 中打开

Make the below changes in your code:

[x,fval]= fsolve(@(x)myfun(x,cpa,cpg,Qin,t2,t1,p1,p2,px,p3,p5,nreg,nc,nt),x0,options);
function F=myfun(x,cpa,cpg,Qin,t2,t1,p1,p2,px,p3,p5,nreg,nc,nt)

Note: You finally get a message that No solution found. Maybe it has something to do with the initial guess but this answer clears all the errors in your code. You would have to figure it out by yourself.