How to solve error for Index exceeds matrix dimensions

I am trying to optimize the PID gains using jaya algorithm objective funcion is at the end But i am getting this error

Index exceeds matrix dimensions.

Error in Jaya_test (line 28) if(fnew(i)<f(i))

if true
function Jaya()
RUNS=1;
runs=0;
while(runs<RUNS)
pop=50; % population size
var=3; % no. of design variables
maxFes=1000;
maxGen=floor(maxFes/pop);
mini=[0 0 0];
maxi=[5 5 5];
[row,var]=size(mini);
x=zeros(pop,var);
for i=1:var
x(:,i)=mini(i)+(maxi(i)-mini(i))*rand(pop,1);%%change
end
ch=1;
gen=0;
f=myobj(x)
while(gen<maxGen)
xnew=updatepopulation(x,f);
xnew=trimr(mini,maxi,xnew);
fnew=myobj(xnew)
for i=1:pop
if(fnew(i)<f(i))
x(i,:)=xnew(i,:);%%change
f(i)=fnew(i);
end
end
disp('%%%%%%Final population%%%%%%%');
disp([x,f]);
fnew=[];xnew=[];
gen=gen+1;
fopt(gen)=min(f);
end
runs=runs+1;
[val,ind]=min(fopt);
Fes(runs)=pop*ind;
best(runs)=val;
end
function[z]=trimr(mini,maxi,x)
[row,col]=size(x);
for i=1:col
x(x(:,i)<mini(i),i)=mini(i);
x(x(:,i)>maxi(i),i)=maxi(i);
end
z=x;
end
function [xnew]=updatepopulation(x,f)
[row,col]=size(x);
[t,tindex]=min(f);
Best=x(tindex,:);
[w,windex]=max(f);
worst=x(windex,:);
xnew=zeros(row,col);
for i=1:row
for j=1:col
r=rand(1,2);
xnew(i,j)=x(i,j)+r(1)*(Best(j)-abs(x(i,j)))-r(2)*(worst(j)-abs(x(i,j)));
end
end
end
function [f]=myobj(x)
  assignin('base', 'Kp', x(1));
  assignin('base', 'Ki', x(2));
  assignin('base', 'Kd', x(3)); 
  sim('PID_TUNING_2.slx'); 
  f = sum(abs(t.*E)).*1e-4;
end

[Torsten]

"f" and "fnew" are scalars in your code, not arrays.

So what do you try to access when you use f(i) and fnew(i) in the for-loop ?

Best wishes

Torsten.

[madhur aggarwal]

f and fnew becomes array after calling the function myobj??

[Torsten]

No. Since you take the sum, both remain scalars.

Best wishes

Torsten.

[madhur aggarwal]

thank you @torsten