how to find unknowns for series of input values?

Do you mean you want to find the values of x and y that satisfy 2*x*2 - 3*y*4 = 100? If so you should be aware that there are an infinite number of solutions!

Or do you mean you want to find the values of x and y that are a best fit to all 4 sets of equations simultaneousy?

32 个评论
显示 30更早的评论隐藏 30更早的评论

Alan Stevens 2020-10-16

编辑：Alan Stevens 2020-10-16

在 MATLAB Online 中打开

Like the following. However, you need to check your equations carefully as well as checking that I've rearranged them correctly:

I=[116 207 414 611 909 1009 951 909 805 615 311 120]; 
Ta=[29 30 31 32 33 34 35 37 36 35 34 33];
Tw1 = 20;
m=100;
n=40;
k=4180;
%E1=I+k*I+k(Tc-T2)==4*k*(T2-Tb);
%E2=m.*I+4.*I+(T2-Tb)==m*(Tb-Tw1);
%E3=2*m.*I+(T1-Tc)==(Tc-Ta)))*I+(Tc-T2);
%E4=3*n*I+(Tg-T1)==(T1-Tc);
%E5=3*I==(Tg-Ta)+(Tg-T1);
%E6=(Tb-Tw1)==(40*k*m*(Tw2-Tw1));
% Rewrite as follows:
% 5*k*T2 -4*k*Tb -k*Tc + 0*T1 + 0*Tg + 0*Tw2  = I*(1+k)
% T2 -(1+m)*Tb + 0*Tc + 0*T1 + 0*Tg + 0*Tw2   = -m*Tw1 - (4+m)*I
% T2 + 0*Tb -(2+I)*Tc + T1 + 0*Tg + 0*Tw2     = -(Ta+2*m)*I
% 0*T2 + 0*Tb - Tc + 2*T1 - Tg + 0*Tw2        = 3*n*I
% 0*T2 + 0*Tb +0*Tc - T1 + 2*Tg + 0*Tw2       = 3*I
% 0*T2 + Tb + 0*Tc + 0*T1 + 0*Tg - 40*k*m*Tw2 = (1+40*k*m)*Tw1
T = zeros(6,numel(I));
for i = 1:numel(I)
    M = [5*k, -4*k,  -k, 0, 0, 0;
         1,   -(1+m), 0, 0, 0, 0;
         1,   0,    -(2+I(i)), 1, 0, 0;
         0, 0, -1, 2, -1, 0;
         0, 0, 0, -1, 2, 0;
         0, 1, 0, 0, 0, -40*k*m];
     V = [(1+k)*I(i);
          -m*Tw1-(4+m)*I(i);
          -(Ta(i)+2*m)*I(i);
          3*n*I(i);
          3*I(i);
          (1+40*k*m)*Tw1];
      T(:,i) = M\V;
end
T2 = T(1,:);
Tb = T(2,:);
Tc = T(3,:);
T1 = T(4,:);
Tg = T(5,:);
Tw2 = T(6,:);
disp(T)