Fmincon problems with A and b matrices that differ depending on for loop

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Hi
Im doing a nonlinear optimization using fmincon that includes nonlinear equality constraints linear inequality constraints (These depend on values from two excel spreadsheets.
This is my code for the A and b matrices for j=1:3 for i=1:5
L = xlsread('hourly electric demand.xlsx');
Lth = xlsread('hourly thermal demand.xlsx');
if xin(1)>= L(j,i) && xin(2)>=Lth(j,i);
A(1,:)=[FIT RHI 0 0 -(FIT-Xe);-1 0 -1 0 0; 0 -1 0 -1 0];
b = [max(Pe*L(j,i))+Pth*max(Lth(j,i))+ Operation; -L(j,i);...
-Lth(j,i)];
elseif xin(1)<=L(j,i) && xin(2)<=Lth(j,i);
A(2,:)=[FIT RHI -Pe -Pth 0;-1 0 -1 0 0; 0 -1 0 -1 0];
b = [max(Pe*L(j,i)+Pth*Lth(j,i))+ Operation;-L(j,i); -Lth(j,i)];
elseif xin(1)>=L(j,i) && xin(2)<=Lth(j,i);
A(3,:)=[FIT RHI 0 -Pth -(FIT-Xe);-1 0 -1 0 0; 0 -1 0 -1 0];
b = [max(Pe*L(j,i)+Pth*Lth(j,i))+ Operation; -L(j,i); -Lth(j,i)];
elseif xin(1)<= L(j,i) && xin(2)>= Lth(j,i);
A(4,:)=[FIT RHI -Pe -Pth 0;-1 0 -1 0 0; 0 -1 0 -1 0];
b = [max(Pe*L(j,i)+Pth*Lth(j,i))+ Operation; -L(j,i); -Lth(j,i)];
end
end
end
and this is the code for the objective function
f = sum(((0.537*(L(j,i)-xin(1)))+(0.185*(Lth(j,i)-xin(2)))));
However I am getting the following error
??? Subscripted assignment dimension mismatch.
Error in ==> invoke at 42 A(1,:)=[FIT RHI 0 0 -(FIT-Xe);-1 0 -1 0 0; 0 -1 0 -1 0];
Do I need to make changes to the objective function since it only includes xin(1) and xin(2) whereas I am constraining to 5 difference xin?
thanks

Accepted Answer

Walter Roberson
Walter Roberson on 3 Jun 2011
[FIT RHI 0 0 -(FIT-Xe);-1 0 -1 0 0; 0 -1 0 -1 0] is clearly 2 dimensional, but you are trying to assign it to a vector A(1,:) . That isn't going to work.
  1 Comment
Andrew Alkiviades
Andrew Alkiviades on 3 Jun 2011
Thanks Walter
I have confused myself quite a bit (and with some basic maths)
do you have any suggestions on solving this issue?
thanks again

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More Answers (1)

Andrew Alkiviades
Andrew Alkiviades on 3 Jun 2011
Thanks Walter
I have confused myself quite a bit (and with some basic maths)
do you have any suggestions on solving this issue?
thanks again
  4 Comments
Andrew Alkiviades
Andrew Alkiviades on 3 Jun 2011
Thanks, I have tried that... Next question :)
i cant seem to find this error anywhere online.
??? Undefined function or method 'isfinite' for input arguments of type 'cell'.
Error in ==> C:\Program Files\MATLAB\R2010b\toolbox\optim\optim\barrier.p>barrier at 24
Do you have any idea what this may be?
Possibly in calling fmincon? which has been done by
options = optimset('Display', 'iter', 'Algorithm','interior-point');
[x,fval,exitflag]=fmincon(@myobjective,x0,A,b,[],[],lb,[],@confun2, options)

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