MATLAB: Ga-fitness

genetic algorithm

Dear All,
I need to optimize parameters of a function using the ga module. I have a coefficient matrix say A(9:4):
A =
   -0.0996   -0.0323   -0.0640   -0.0365
    0.0859   -0.0636    0.0552    0.0315
    0.1805    0.0125    0.1159    0.0662
    0.0521    0.0513    0.0335    0.0191
   -0.3028    0.0647   -0.1946   -0.1111
   -0.2242   -0.0382   -0.1440   -0.0822
    0.0475   -0.0191    0.0305    0.0174
    0.2170   -0.0010    0.1394    0.0796
    0.0437    0.0257    0.0281    0.0160
and a vector B where i store the experimental data say B(9:1):
B =
   -4.8700
   -3.2100
    5.1000
    5.3400
   -1.6200
   -8.1700
   -0.4700
    4.8300
    3.0800
my chromosome will be a vector x(4:1)
I would like to write a fitness function like:
fitnessfcn = abs((A*x)-B) [x,fval]=ga(fitnessfcn,4)
I have used the below function
FitnessFcn = @(x) abs( ((A(1,1)*x(:,1))+(A(1,2)*x(:,2))+(A(1,3)*x(:,3))+(A(1,4)*x(:,4)))-B(1,1))
which only uses (the first row of A) * (column x)-(first element of B)
How can I write in general form to use all the data. I have tried fitnessfcn = abs((A*x)-B) but it says Error using ==> mtimes Inner matrix dimensions must agree.
Do I have to use for loops and how to write a function with for loops?
I would really welcome any sugestion.
Kind regards, Christos

Best Answer

variant
FitnessFcn = @(x)bsxfun(@minus,abs(bsxfun(@times,A,x)),B)
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