Error with passing a fitness function into a GA command

Hi There,

I created a fitness function in an m file called NSD_Fitness as follows:

*******************************************

function y = NSD_Fitness(X)
global CombinedYieldRank CombinedPPIRank r
y = 1/...
(   ( X(1) + X(2) + X(3)  ) * ( r * CombinedYieldRank(1,1) + (1-r) * CombinedPPIRank(1,1) ) + 	( X(4) + X(5) + X(6)  ) * ( r * CombinedYieldRank(1,2) + (1-r) * CombinedPPIRank(1,2) ) + 	( X(7) + X(8) + X(9)  ) * ( r * CombinedYieldRank(1,3) + (1-r) * CombinedPPIRank(1,3) ) + 	( X(10) + X(11) + X(12)  ) * ( r * CombinedYieldRank(1,4) + (1-r) * CombinedPPIRank(1,4) ) + ...
...
    ( X(85) + X(86) + X(87)  ) * ( r * CombinedYieldRank(8,1) + (1-r) * CombinedPPIRank(8,1) ) + 	( X(88) + X(89) + X(90)  ) * ( r * CombinedYieldRank(8,2) + (1-r) * CombinedPPIRank(8,2) ) + 	( X(91) + X(92) + X(93)  ) * ( r * CombinedYieldRank(8,3) + (1-r) * CombinedPPIRank(8,3) ) + 	( X(94) + X(95) + X(96)  ) * ( r * CombinedYieldRank(8,4) + (1-r) * CombinedPPIRank(8,4) )  );
end

*******************************************

In another m file called NSD_Main, I used below statement to create a function handle of NSD_Fitness and passed it into a GA command like below:

*******************************************

...

FitFcn = @NSD_Fitness;
options = optimoptions( 'ga','ConstraintTolerance',1e-3,'CreationFcn',[],'MaxStallGenerations',500,...
                        'FunctionTolerance',0,'PopulationSize',200,...
                        'CrossoverFraction',0.9,...
                        'PlotFcn',{@gaplotbestf,@gaplotstopping});
[x,Fval,exitFlag,Output] = ga(FitFcn,nvars,A,b,Aeq,beq,lb,ub,nonlcon,IntCon,options);

*******************************************

Interestingly, I was able to see the GA plots but received the error message below after:

*******************************************

Undefined function 'NSD_Fitness' for input arguments of type 'double'.

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

Error in gapenalty

Error in gapenalty

Error in gaminlp

Error in ga (line 394)
    [x,fval,exitFlag,output,population,scores] = gaminlp(FitnessFcn,nvars, ...

Error in NSD_Main (line 169)
[x,Fval,exitFlag,Output] = ga(FitFcn,nvars,A,b,Aeq,beq,lb,ub,nonlcon,IntCon,options);
 

*******************************************

All the other parts of my code have been checked correct except for the function handle. What's wrong and how should I code it? Thank you very much.

[Geoff Hayes]

Ling - in your second call to ga

ga(@(x)NSD_Fitness(x,{CombinedYieldRank,CombinedPPIRank,r})

what are you trying to do with the above?

[Ling Kev]

Hi Geoff,

Thanks for your prompt response. Please ignore the previous coding. What I wrote is actually as follows:

[x,Fval,exitFlag,Output] = ga(FitFcn,nvars,A,b,Aeq,beq,lb,ub,nonlcon,IntCon,options);

Then I get the error message as now shown in my post.

Answer 1

[Star Strider]

This is a bit confusing.

First, ‘NSD_Fitness’ should be:

function y = NSD_Fitness(X,CombinedYieldRank,CombinedPPIRank,r)
y = 1/...
(   ( X(1) + X(2) + X(3)  ) * ( r * CombinedYieldRank(1,1) + (1-r) * CombinedPPIRank(1,1) ) + 	( X(4) + X(5) + X(6)  ) * ( r * CombinedYieldRank(1,2) + (1-r) * CombinedPPIRank(1,2) ) + 	( X(7) + X(8) + X(9)  ) * ( r * CombinedYieldRank(1,3) + (1-r) * CombinedPPIRank(1,3) ) + 	( X(10) + X(11) + X(12)  ) * ( r * CombinedYieldRank(1,4) + (1-r) * CombinedPPIRank(1,4) ) + ...
...
    ( X(85) + X(86) + X(87)  ) * ( r * CombinedYieldRank(8,1) + (1-r) * CombinedPPIRank(8,1) ) + 	( X(88) + X(89) + X(90)  ) * ( r * CombinedYieldRank(8,2) + (1-r) * CombinedPPIRank(8,2) ) + 	( X(91) + X(92) + X(93)  ) * ( r * CombinedYieldRank(8,3) + (1-r) * CombinedPPIRank(8,3) ) + 	( X(94) + X(95) + X(96)  ) * ( r * CombinedYieldRank(8,4) + (1-r) * CombinedPPIRank(8,4) )  );
end

Get rid of the global variables. Note that ‘y’ must be a scalar value.

Second, ‘FitFcn’ must be defined as:

FitFcn = @(X) NSD_Fitness(X,CombinedYieldRank,CombinedPPIRank,r);

then this should work:

[x,Fval,exitFlag,Output] = ga(FitFcn,nvars,A,b,Aeq,beq,lb,ub,nonlcon,IntCon,options);

I obviously cannot test that, so you will need to.