Vectors must be the same lengths. how to solve this error

clear;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% PARAMETERS %%%%%%%%%%%%%%%%%%%%%%%%%%%%

%Field Dimensions - x and y maximum (in meters)
xm=100;
ym=100;

%x and y Coordinates of the Sink
sink.x=0.5*xm;
sink.y=0.5*ym;

%Number of Nodes in the field
n=100;

%Optimal Election Probability of a node
%to become cluster head
p=0.1;

%Energy Model (all values in Joules)
%Initial Energy 
Eo=0.5;
%Eelec=Etx=Erx
ETX=50*0.000000001;
ERX=50*0.000000001;
%Transmit Amplifier types
Efs=10*0.000000000001;
Emp=0.0013*0.000000000001;
%Data Aggregation Energy
EDA=5*0.000000001;

%Values for Hetereogeneity
%Percentage of nodes than are advanced
m=0.1;
%\alpha
a=1;

%maximum number of rounds
rmax=99;

%%%%%%%%%%%%%%%%%%%%%%%%% END OF PARAMETERS %%%%%%%%%%%%%%%%%%%%%%%%

%Computation of do
do=sqrt(Efs/Emp);



%Creation of the random Sensor Network
figure(1);
for i=1:1:n
    S(i).xd=rand(1,1)*xm;
    XR(i)=S(i).xd;
    S(i).yd=rand(1,1)*ym;
    YR(i)=S(i).yd;
    S(i).G=0;
    %initially there are no cluster heads only nodes
    S(i).type='N';
   
    temp_rnd0=i;
    %Random Election of Normal Nodes
    if (temp_rnd0>=m*n+1) 
        S(i).E=Eo;
        S(i).ENERGY=0;
        plot(S(i).xd,S(i).yd,'o');
        hold on;
    end
    %Random Election of Advanced Nodes
    if (temp_rnd0<m*n+1)  
        S(i).E=Eo*(1+a)
        S(i).ENERGY=1;
        plot(S(i).xd,S(i).yd,'+');
        hold on;
    end
end


S(n+1).xd=sink.x;
S(n+1).yd=sink.y;
plot(S(n+1).xd,S(n+1).yd,'x');

%First Iteration
figure(1);

flag_first_dead=0;

for r=0:1:rmax
    r

  %Operation for epoch
  if(mod(r, round(1/p) )==0)
    for i=1:1:n
        S(i).G=0;
        S(i).cl=0;
    end
  end
end
hold off;

%Number of dead nodes
dead=0;
%Number of dead Advanced Nodes
dead_a=0;
%Number of dead Normal Nodes
dead_n=0;

%counter for bit transmitted to Bases Station and to Cluster Heads
packets_TO_BS=0;
packets_TO_CH=0;
%counter for bit transmitted to Bases Station and to Cluster Heads 
%per round
PACKETS_TO_CH(r+1)=0;
PACKETS_TO_BS(r+1)=0;

figure(1);

for i=1:1:n
    %checking if there is a dead node
    if (S(i).E<=0)
        plot(S(i).xd,S(i).yd,'red .');
        dead=dead+1;
        if(S(i).ENERGY==1)
            dead_a=dead_a+1;
        end
        if(S(i).ENERGY==0)
            dead_n=dead_n+1;
        end
        hold on;    
    end
    if S(i).E>0
        S(i).type='N';
        if (S(i).ENERGY==0)  
        plot(S(i).xd,S(i).yd,'o');
        end
        if (S(i).ENERGY==1)  
        plot(S(i).xd,S(i).yd,'+');
        end
        hold on;
    end
end
plot(S(n+1).xd,S(n+1).yd,'x');


STATISTICS(r+1).DEAD=dead;
DEAD(r+1)=dead;
DEAD_N(r+1)=dead_n;
DEAD_A(r+1)=dead_a;

%When the first node dies
if (dead==1)
    if(flag_first_dead==0)
        first_dead=r
        flag_first_dead=1;
    end
end


for i=1:1:n
   if(S(i).E>0)
   temp_rand=rand;     
     if ( (S(i).G)<=0)
              
 %Election of Cluster Heads
    hold on;
    S(i).xd=rand(1,n)*xm;
    S(i).yd=rand(1,n)*ym;
    k=100;
    CHx=kmeans(S(i).xd,k);
    CHy=kmeans(S(i).yd,k);
    plot(CHx,CHy,'r*')
    packets_TO_BS=packets_TO_BS+1;
    PACKETS_TO_BS(r+1)=packets_TO_BS; 
    distance=sqrt( (S(i).xd-(S(n+1).xd) ).^2 + (S(i).yd-(S(n+1).yd) ).^2 );
%Calculation of Energy dissipated
            distance;
            if (distance>do)
                S(i).E=S(i).E- ( (ETX+EDA).*(4000) + Emp.*4000.*( distance.*distance.*distance.*distance )); 
            end
            if (distance<=do)
                S(i).E=S(i).E- ( (ETX+EDA).*(4000)  + Efs.*4000.*( distance .* distance )); 
            end
        end     
    
   end
   sum=0;
for i=1:1:n
if(S(i).E>0)
    sum=sum+S(i).E;
end
end
avg=sum/n;
STATISTICS(r+1).AVG=avg;
sum;
end
 
figure(2);
for r=0:1:99
    ylabel('Average Energy of Each Node');
    xlabel('Round Number');
    plot([r r+1],[STATISTICS(r+1).AVG STATISTICS(r+2).AVG],'blue');
    hold on;

end

figure(3);
for r=0:1:249
    ylabel('Number of Dead Nodes');
    xlabel('Round Number');
    plot([r r+1],[STATISTICS(r+1).DEAD STATISTICS(r+2).DEAD],'blue');
    hold on;
end

Vectors must be the same lengths.

Answer 1

[Walter Roberson]

    STATISTICS(r+1).AVG=avg;

r is not changing inside that loop, so you are always overwriting the same location, and all of the other ones come out empty.

[Catherine tadros]

how to solve this??

[Walter Roberson]

    STATISTICS(i).AVG=avg;