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

Hello everyone !

I'm currently trying to use a genetic algorithm for a simple problem, but it fails and I don't know why. This is my first time using a genetic algorithm function.

I have a function AlgoGen with 3 variables:

[Sol] = AlgoGen(alpha,beta,gamma).

That I can calculate if I try several inputs, so this function works. But when I'm trying to use:

SOL = ga(@(x) AlgoGen(x),3,[],[],[],[],[1 2.25*10^-2 1],[5 15*10^-2 5])

This is the error message I get:

Not enough input arguments.

Error in AlgoGen (line 5)
length=[1 0.75 1 1 alpha gamma]*10^-2;

Error in @(x)AlgoGen(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 374)
            [x,fval,exitFlag,output,population,scores] = galincon(FitnessFcn,nvars, ...

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

Anyone can help me ? Thank you.

[VIGNESH KUMAR R C]

This is my Cost Function definition:

function f = costFn(i_d, i_q)

L_d = 100e-6;

L_q = 500e-6;

lambda_f = 0.01;

P = 6;

T_e = 2.5;

f = (T_e - (3/2)*(P/2)*(lambda_f.*i_q + (L_d-L_q).*i_d.*i_q)).^2;

end

This is how I am trying to implement ga:

clc;

clear;

type costFn

fun = @(i_d, i_q)(costFn(i_d, i_q));

fsurf(fun, [-50 50 -50 50])

colormap 'parula'

xlabel('i_d')

ylabel('i_q')

sol = ga(fun,2);

I am getting same error as above. Kindly help me out.

Answer 1

[Star Strider]

You need to supply a function with a single vector argument to ga.

This should work:

SOL = ga(@(x) AlgoGen(x(1),x(2),x(3)),3,[],[],[],[],[1 2.25*10^-2 1],[5 15*10^-2 5])

Here, ‘x(1)=alpha’, ‘x(2)=beta’ and ‘x(3)=gamma’.

No other changes to your code should be necessary.

[Nicolas]

Oh yes ! What a mistake... Thanks a lot !

It was quick

[Star Strider]

As always, my pleasure!

If my Answer helped you solve your problem, please Accept it!