How to fix "Subscripted assignment dimension mismatch," in a for loop?

for k=1:length(index)

syms w

   W_TO(k) = vpasolve(((C1(k)+C5(k))*(w^1.195))+(C2*(w^.235))+((C3+C4(k)+C6(k)+C7+C10-1)*w)+(C8+C9)==0,w);

end

The error message I get it is: "Subscripted assignment dimension mismatch.

Error in sym/privsubsasgn (line 1107) L_tilde2 = builtin('subsasgn',L_tilde,struct('type','()','subs',{varargin}),R_tilde);

Error in sym/subsasgn (line 944) C = privsubsasgn(L,R,inds{:});

Error in Weight (line 250) W_TO(k) = vpasolve(((C1(k)+C5(k))*(w^1.195))+(C2*(w^.235))+((C3+C4(k)+C6(k)+C7+C10-1)*w)+(C8+C9)==0,w);"

For each k value, I should be getting one value for W_TO. My guess is that there is no analytical solution to this expression. I would appreciate the advice anyone can give on fixing this issue.

Answer 1

[Star Strider]

I cannot run your code because I do not have the constants.

Your guess may be correct. However saving ‘W_TO’ as a cell array instead may at least prevent the error your code is currently throwing:

W_TO{k} = vpasolve(((C1(k)+C5(k))*(w^1.195))+(C2*(w^.235))+((C3+C4(k)+C6(k)+C7+C10-1)*w)+(C8+C9)==0,w);

You can sort out any multiple results for each ‘k’ iteration after the loop completes.

[Alec Carruthers]

You are right about using a cell array for "W_TO" because that fixed the issue. However, now I get three outputs of "[]"? Im not sure what that means.

[Walter Roberson]

MATLAB was not able to find numeric solutions for those three cases. Possibly they do not exist, or possibly it is just too hard for MATLAB.

[Alec Carruthers]

Alright, that is what I was thinking.

Thank You!