# "Subscripted assignment dimension mismatch.' when running a linprog coding.

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Andrew Alkiviades on 21 Jun 2012
"Subscripted assignment dimension mismatch.' when running a linprog coding.
My code is
for M = 1 : size(PV_output,1)
for N = 1 : size(WT_output,2)
f(:,M:N ) = [((CRF*CC_PV(M)/PVenergy(M)+OM_PV)); ((CRF*CC_WT(N))/WTenergy(N))+OM_WT]; % Objective function coefficients
%A(:,:) = [-PV_output(:,:,K) -WT_output(:,:,L)];
A (:,M,N) = [-PV_output(:,M) -WT_output(:,N) ];
b(:,:) = -Demand(:);
lb = zeros(2,1);
ub = [max_PV_area/PV_area; max_WT_area/WT_area]';
end
end
[x, fval, exitflag] = linprog(f,A,b,[],[],lb,ub)
PV_output is 8760x1x27 and WT_output is 8760x1x3
I am trying to find the "f" coefficients below for all the combinations of the 27 and 3 PV and WT's in this code Does anyone know how to index the "f" to do so?
Thank you

Sean de Wolski on 21 Jun 2012
Huh?
You could squeeze() it to remove the singleton dimension.

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Andrew Alkiviades on 21 Jun 2012
no, one size is (8760,1,m) and the other is (8760,1,n)
and I want to code "f" and "A" matrices for all the m and n combinations.
where m is 27 and n is 3
hope this is clearer
Sean de Wolski on 21 Jun 2012
So why are they 3d matrices and not just two, considering that there is only 1 column and thus it is essentially a 2d matrix permuted into the third dimension?
And, what you have here is _exactly_ what I said in my reply, if m, n are 1.
Sean de Wolski on 21 Jun 2012
(*) m is 8760, n is 1

### More Answers (1)

Andrew Alkiviades on 21 Jun 2012
If I have understood correctly, I have adapted my code to your suggestions
A = cell(27,3);
for ii = 1:27
PV = PV_output(:,:,ii);
for jj = 1:3
WT = WT_output(:,:,ii);
A(ii,jj) = [PV WT];
f = [((CRF*CC_PV(PV)/PVenergy(PV)+OM_PV)); ((CRF*CC_WT(WT))/WTenergy(WT))+OM_WT]; % Objective function coefficients
end
end
I am not sure of the
A(ii,jj) = [PV WT];
as it stands i have an error on the A(ii,jj) = [PV WT] line of "Conversion to cell from double is not possible." What alterations can I make to "A" that will allow me to directly use it as the inequality constraint matrix in linprog? I require A to be a 8760x2x81 matrix - if so can this matrix be used in the Ax<=b form that linprog requires so that I can optimise and select from all the PV and WT combinations?

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Andrew Alkiviades on 21 Jun 2012
However, matlab doesn't like this concatenation as I get the "Conversion to cell from double is not possible.
" error!
Sean de Wolski on 21 Jun 2012
That was a typo, you will want:
A{ii,jj}, note the xcurly '{' which indicates conversion. The regular parenthesis assumes it is a cell already and that is why you see the error.
Andrew Alkiviades on 21 Jun 2012
Thanks, I think we are getting there!
I can run without errors on these lines but I can access any array or element in A, when I run for A i get
A = [8760x2 double] [ ] [ ] for 27 rows which I am assuming is all the array combinations possible?