# why does this code give an error ( Undefined function or variable 'ObjectiveFunction'. Error in psi_kozhin (line 44) Swarm.Particles(k).O = fobj(currentX); )?

9 views (last 30 days)
Kozhin Tariq on 16 Mar 2021
Answered: Alan Weiss on 18 Mar 2021
clear all
close all
clc
% Define the details of the table design problem
nVar = 2;
ub = [10 10];
lb = [-10 -10];
fobj = @ObjectiveFunction;
% Define the PSO's paramters
noP = 30;
maxIter = 50;
wMax = 0.9;
wMin = 0.2;
c1 = 2;
c2 = 2;
vMax = (ub - lb) .* 0.2;
vMin = -vMax;
% The PSO algorithm
% Initialize the particles
for k = 1 : noP
Swarm.Particles(k).X = (ub-lb) .* rand(1,nVar) + lb;
Swarm.Particles(k).V = zeros(1, nVar);
Swarm.Particles(k).PBEST.X = zeros(1,nVar);
Swarm.Particles(k).PBEST.O = inf;
Swarm.GBEST.X = zeros(1,nVar);
Swarm.GBEST.O = inf;
end
% Main loop
for t = 1 : maxIter
% Calcualte the objective value
for k = 1 : noP
currentX = Swarm.Particles(k).X;
Swarm.Particles(k).O = fobj(currentX);
% Update the PBEST
if Swarm.Particles(k).O < Swarm.Particles(k).PBEST.O
Swarm.Particles(k).PBEST.X = currentX;
Swarm.Particles(k).PBEST.O = Swarm.Particles(k).O;
end
% Update the GBEST
if Swarm.Particles(k).O < Swarm.GBEST.O
Swarm.GBEST.X = currentX;
Swarm.GBEST.O = Swarm.Particles(k).O;
end
end
% Update the X and V vectors
w = wMax - t .* ((wMax - wMin) / maxIter);
for k = 1 : noP
Swarm.Particles(k).V = w .* Swarm.Particles(k).V + c1 .* rand(1,nVar) .* (Swarm.Particles(k).PBEST.X - Swarm.Particles(k).X) ...
+ c2 .* rand(1,nVar) .* (Swarm.GBEST.X - Swarm.Particles(k).X);
% Check velocities
index1 = find(Swarm.Particles(k).V > vMax);
index2 = find(Swarm.Particles(k).V < vMin);
Swarm.Particles(k).V(index1) = vMax(index1);
Swarm.Particles(k).V(index2) = vMin(index2);
Swarm.Particles(k).X = Swarm.Particles(k).X + Swarm.Particles(k).V;
% Check positions
index1 = find(Swarm.Particles(k).X > ub);
index2 = find(Swarm.Particles(k).X < lb);
Swarm.Particles(k).X(index1) = ub(index1);
Swarm.Particles(k).X(index2) = lb(index2);
end
outmsg = ['Iteration# ', num2str(t) , ' Swarm.GBEST.O = ' , num2str(Swarm.GBEST.O)];
disp(outmsg);
cgCurve(t) = Swarm.GBEST.O;
end
semilogy(cgCurve);
xlabel('Iteration#')
ylabel('Weight')

Alan Weiss on 18 Mar 2021
I do not see where you defined ObjectiveFunction. Is it on your MATLAB path?
Alan Weiss
MATLAB mathematical toolbox documentation

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