How can I fix the "matrix dimensions must agree" errors in ga

hi,

when I run the optimtool , I see the "matrix dimensions must agree" .

how can I fix it? I think I can't write the fitness funct. correctly.

my fitness funct;

I try to write sum((i,j),x(i,j)*a(i,j))

a=[1000000 1                   1             0        1         0; 1       1000000             0             1        0         1;1       0                   1000000       1        1         0;   0       1                   1             1000000  0         1;1       0                   1             0        1000000   1;   0       1                   0             1        1         1000000 ] ;
  
y=(sum(sum(a.*x))) ;

is it true?

and linear eq like this;

T = ones(1,6);
Aeq = blkdiag(T,T,T,T,T,T)
beq = ones(6,1)

[Geoff Hayes]

Baris - please copy and paste the full error message (all the red text) to this question.

[Baris Karakum]

Optimization running.

Error running optimization.

Matrix dimensions must agree.

[Baris Karakum]

when I try it in script,ı take this error massages;

Matrix dimensions must agree.

Error in arrangement_obj (line 12)

y=sum(sum(a.*x)) ;

Error in createAnonymousFcn>@(x)fcn(x,FcnArgs{:}) (line 11)

fcn_handle = @(x) fcn(x,FcnArgs{:});

Error in makeState (line 47)

firstMemberScore = FitnessFcn(state.Population(initScoreProvided+1,:));

Error in galincon (line 17)

state = makeState(GenomeLength,FitnessFcn,Iterate,output.problemtype,options);

Error in ga (line 401)

[x,fval,exitFlag,output,population,scores] = galincon(FitnessFcn,nvars, ...

Error in Untitled (line 6)

[x,fval]=ga(@arrangement_obj,36,Aeq,beq);

Caused by:

Failure in initial user-supplied fitness function evaluation. GA cannot continue.

[Geoff Hayes]

So the error appears to be with

y=sum(sum(a.*x)) ;

where a is a 6x6 matrix. What are the dimensions of x? Presumably that is the input to the fitness function but is it a 6x6 or just a 6x1? I'm guessing that the

"matrix dimensions must agree" 

error is due to the

a.*x

Please confirm the dimensions of x and the multiplication operation that you are performing.

[Baris Karakum]

x is a 6x6 matrix.

[Geoff Hayes]

what is x? how or where is it set?

[Baris Karakum]

it is an variable. I write 36 in nvars section. lower bounds = zeros(6,6) upper bounds=(6,6).

I want to find x values. I assume if x(2,1)=1 number two can sit next to 1. The problem is about sitting arrangement for dinner.

[Geoff Hayes]

if nvars is 36, then how do you know that x is 6x6? why can't t be 36x1 instead? Have you verified the dimensions of this input?

I don't understand what you mean by lower bounds = zeros(6,6) upper bounds=(6,6).

[Baris Karakum]

actally,I don't know and I asked for it. And someone say just write 36 in nvars section and nothing other. and I mean lower bound for x is 6x6 zero matrix and upper bounds for x is 6x6 matrix that include just ones.

And I can run without errors by changing fitness function like ;

y=(sum(a(:).*x(:))) ;

and thanks very very much for your interest and time.

[Geoff Hayes]

if it works when you do (where A(:) reshapes all elements of A into a single column vector.)

a(:).*x(:)

then that suggests that they are of different dimensions...and most likely the input x is a column array.

[Baris Karakum]

but the output is 6x6 matrix(for x) and it's true but actually I am new to Matlab. I wrote this problems in GAMS. so,maybe I do something wrong but for now it is true at least.

[Geoff Hayes]

Baris - I'm not sure what GAMS is; and I don't know what you mean by the output is 6x6 matrix(for x).