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for loop doesn't seem to loop

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Hi I have the following code
for i = 1:8760
A = [PVtech(i,:) WTtech(i,:)];
b = demand(i);
f = [CRF*PVtechcost(i,:).*PVcap(i,:)./PVtech(i,:) CRF*WTtechcost(i,:).*WTcap(i,:)./WTtech(i,:)];
x(i) = linprog(f, A,b,[], [], lb);
end
I am trying to optimise linprog over the 8760 data set but I can't seem to get the loop going for each row. therefore when I run it is get a size of A to be 1x30 (when it should be 8760 by 30) Does anyone see where I have coded wrongly ?
thank you

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Accepted Answer

Ryan
Ryan on 3 Jul 2012
You're not specifying the row of A that you are writing the data to, so each loop it just places [PVtech(i,:) WTtech(i,:)] into the first row of A.
Try:
for m = 1:8760
A(m,:) = [PVtech(m,:) WTtech(m,:)];
b = demand(m);
f = [CRF*PVtechcost(m,:).*PVcap(m,:)./PVtech(m,:) CRF*WTtechcost(m,:).*WTcap(m,:)./WTtech(m,:)];
x(m) = linprog(f, A,b,[], [], lb);
end

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Sean de Wolski
Sean de Wolski on 3 Jul 2012
same with x I believe.

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More Answers (2)

Thomas
Thomas on 3 Jul 2012
Edited: Thomas on 3 Jul 2012
use ii instead of i since i is built into matlab for complex numbers
for ii=1:8760
ii % to show which loop you are in
A(ii,:)=[PVtech(ii,:) WTtech(ii,:)];
You also might have to change your
x(ii,:) = linprog(f, A(ii,:),b,[], [], lb)
Though I do feel that your program was running right just that you were only seeing the last A which will be 1x30 since it was being overwritten.
to see if you are going through the loop
just output ii

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Andrew Alkiviades
Andrew Alkiviades on 3 Jul 2012
Still no luck! the ii output returns - 1 the size of A is still (1,30) and the size of b is still (1,1) A should be (8760x30) and b should be 8760x1
Ryan
Ryan on 3 Jul 2012
Are you sure that you are showing us everything that is happening in the code? Doing something simplified such as:
for ii = 1:8760
A(ii,:) = 1;
end
returns an 8760x1 vector for me.

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Andrew Alkiviades
Andrew Alkiviades on 3 Jul 2012
Thanks guys - I have made the changes you suggest,
I now get, from the code below, two rows of A so I have a size(A) = (2,30) where A should in fact be 8760x30
I don't see why the loop doesn't go through all the 8760 rows as it is
for i = 1:8760
A(i,:) = [PVtech(i,:) WTtech(i,:)];
b = demand(i);
f = [CRF*PVtechcost(i,:).*PVcap(i,:)./PVtech(i,:) CRF*WTtechcost(i,:).*WTcap(i,:)./WTtech(i,:)];
%options == optimset('LargeScale', 'off', 'Simplex', 'on');
x(i,:) = linprog(f, A,b,[], [], lb,[])
end

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