Unable to perform the assignment because the left & the right side have a different number of elements

I'm getting the error as stated in the title. I can't figure out why. We should be able to assign scalar values to array elements like a[0]=2,a[5]=5, etc

So why is it giving me an arror in the line : average=avg

attached is the full code for your reference:

clear;

close all;

clc;

ad=-99;

% PARAMETER initialization

%Number of Nodes in the field

% n=200;

fd=-99;

n=300;

%Energy Model (all values in Joules)

%Initial Energy

Eo=0.5;

%Field Dimensions - x and y maximum (in meters)

% xm=input('Enter x value for area plot : ');

% ym=input('Enter y value for area plot : ');

xm=100;

ym=100;

%message size in bits

l=2000;

%x and y Coordinates of the Sink

sink.x=0.5*xm;

sink.y=0.5*ym;

%Optimal Election Probability of a node

%to become cluster head

p=0.1;

ETX=50*0.000000001;

ERX=50*0.000000001;

Eelec=ETX;

%Transmit Amplifier types

Efs=10*0.000000000001;

Emp=0.0013*0.000000000001;

%Data Aggregation Energy

EDA=5*0.000000001;

%Values for Hetereogeneity

%fraction of nodes than are advanced

m=0.1;

%alpha

a=2;

%beta

b=3;

flag_ad=0;

%maximum number of rounds

rmax=300;

CLUSTERHS=zeros(rmax);

%optimal number of cluster heads

k=30;% optimal number of cluster heads = 0.1 of 300 nodes

rcountCHs=zeros(rmax);

%Computation of do

do=sqrt(Efs/Emp);

%Creation of the random Sensor Network

figure(1);

plot(sink.x,sink.y,'X');

%creating the cluster head threshold array

thresh=zeros(1,n);

%creating a cluster head probability array

P=zeros(1,n);

hold off;

t=0;

S(n+1).xd=sink.x;

S(n+1).yd=sink.y;

S(1).E=Eo*(n*(1-m)+n*m*(1+b));

x1=40;

y1=40;

x2=60;

y2=60;

a2=100;

b2=100;

%initializing the balanced influential factor

psi=zeros(n,rmax);

%distance to the base station for all nodes in WSN

d=zeros(n);

%Optimal Election Probability of a node

%to become cluster head taken to be 10%

prob=0.1;

%sink placed at the center of the field

S(n+1).xd=0.5*100;

S(n+1).yd=0.5*100;

%number of normal and advanced nodes

n_normal=0;

n_advanced=0;

%C.d=zeros(n);

n_alive=0;

Energy_disp=zeros(1,rmax);

%avgdist=0;

first=0;

h(1).xd=25;%helper node 1 x coordinate

h(1).yd=45;%helper node 1 y coordinate

h(1).E=Eo*(1+a);%initial energy of the helper node

h(2).xd=75;%helper node 2 x coordinate

h(2).yd=45;%helper node 2 y coordinate

h(2).E=Eo*(1+a);

h(3).xd=25;%helper node 3 x coordinate

h(3).yd=55;%helper node 3 y coordinate

h(3).E=Eo*(1+a);

h(4).xd=75;%helper node 4 x coordinate

h(4).yd=55;%helper node 4 y coordinate

for i=1:1:n/4

C(i).id=1;

S(i).xd=rand(1,1)*x1;

S(i).yd=rand(1,1)*y1;

S(i).d=sqrt( (S(i).xd-(h(1).xd) )^2 + (S(i).yd-(h(1).yd) )^2 );%distance to helper node

S(i+n/4).d=sqrt( (S(i+n/4).xd-(h(2).xd) )^2 + (S(i+n/4).yd-(h(2).yd) )^2 );

S(i+n/2).d=sqrt( (S(i+n/2).xd-(h(3).xd) )^2 + (S(i+n/2).yd-(h(3).yd) )^2 );

S(i+3*n/4).d=sqrt( (S(i+3*n/4).xd-(h(4).xd) )^2 + (S(i+3*n/4).yd-(h(4).yd) )^2 );

XR(i)=S(i).xd;

YR(i)=S(i).yd;

plot(S(i).xd,S(i).yd,'s');

xlim([0 100]);

ylim([0 100]);

S(i).G=0;

S(i).type='N';

C(i+n/4).id=2;

S(i+n/4).xd=(a2-x2).*rand(1,1)+x2;

S(i+n/4).yd=(b2-y2).*rand(1,1)+y2;

plot(S(i+n/4).xd,S(i+n/4).yd,'s');

xlim([0 100]);

ylim([0 100]);

S(i+n/4).G=0;

S(i+n/4).type='N';

S(i+n/2).xd=(a2-x2).*rand(1,1)+x2;

S(i+n/2).yd=y1*rand(1,1);

plot(S(i+n/2).xd,S(i+n/2).yd,'s');

xlim([0 100]);

ylim([0 100]);

C(i+n/2).id=4;

S(i+3*n/4).G=0;

S(i+3*n/4).type='N';

S(i+3*n/4).xd=x2*rand(1,1);

S(i+3*n/4).yd=(b2-y2).*rand(1,1)+y2;

C(i+3*n/4).id=3;

plot(S(i+3*n/4).xd,S(i+3*n/4).yd,'s');

plot(S(n+1).xd,S(n+1).yd,'x');%base station

xlim([0 100]);

ylim([0 100]);

S(i+3*n/4).G=0;

S(i+3*n/4).type='N';

hold on;

%Random Election of Normal Nodes

if(n_normal<(n-(m*n)))

S(i).type='N';

S(i).E=Eo;

plot(S(i).xd,S(i).yd,'s');

S(i+n/4).type='N';

S(i+n/4).E=Eo;

plot(S(i+n/4).xd,S(i+n/4).yd,'s');

n_normal=n_normal+1;

S(i+n/2).type='N';

S(i+n/2).E=Eo;

n_normal=n_normal+1;

plot(S(i+n/2).xd,S(i+n/2).yd,'s');

S(i+3*n/4).type='N';

S(i+3*n/4).E=Eo;

n_normal=n_normal+1;

plot(S(i+3*n/4).xd,S(i+3*n/4).yd,'s');

hold on;

end

if(n_advanced<n*m+1)

S(i).type='A';

S(i).E=Eo*(1+a);

S(i).Energy=1;

n_advanced=n_advanced+1;

plot(S(i).xd,S(i).yd,'+');

S(i+n/4).type='A';

S(i+n/4).E=Eo*(1+a);

S(i+n/4).Energy=1;

n_advanced=n_advanced+1;

plot(S(i+n/4).xd,S(i+n/4).yd,'+');

S(i+n/2).type='A';

S(i+n/2).E=Eo*(1+a);

S(i+n/2).Energy=1;

n_advanced=n_advanced+1;

plot(S(i+n/2).xd,S(i+n/2).yd,'+');

S(i+3*n/4).type='A';

S(i+3*n/4).E=Eo*(1+a);

S(i+3*n/4).Energy=1;

n_advanced=n_advanced+1;

plot(S(i+3*n/4).xd,S(i+3*n/4).yd,'+');

hold on;

end

end

h(1).d=sqrt( (S(n+1).xd-(h(1).xd) )^2 + (S(n+1).yd-(h(1).yd) )^2 );%distance from the helper node 1

h(2).d=sqrt( (S(n+1).xd-(h(2).xd) )^2 + (S(n+1).yd-(h(2).yd) )^2 );%distance from the helper node 2

h(3).d=sqrt( (S(n+1).xd-(h(3).xd) )^2 + (S(n+1).yd-(h(3).yd) )^2 );%distance from the helper node 3

h(4).d=sqrt( (S(n+1).xd-(h(4).xd) )^2 + (S(n+1).yd-(h(4).yd) )^2 );%distance from the helper node 4

plot(h(1).xd,h(1).yd,'x');

plot(h(2).xd,h(2).yd,'x');

plot(h(3).xd,h(3).yd,'x');

plot(h(4).xd,h(4).yd,'x');

h(1).E=Eo*(1+a);

h(2).E=Eo*(1+a);

h(3).E=Eo*(1+a);

h(4).E=Eo*(1+a);

h(1).type='A';

h(2).type='A';

h(3).type='A';

%flag_fd=0;

flag_hd=0;

hd1=-999;

average=zeros(1,rmax);

davgbs=0;

%plot(S(n+1).xd,S(n+1).yd,'o', 'MarkerSize', 12, 'MarkerFaceColor', 'r');

figure(1);

% figure(1)

%plot(o1,o2,'^','LineWidth',1, 'MarkerEdgeColor','k', 'MarkerFaceColor','y', 'MarkerSize',12);

% hold on

%First Iteration

%counter for CHs

countCHs=0;

%counter for CHs per round

%rcountCHs=0;

cluster=1;

%countCHs;

%rcountCHs=rcountCHs+countCHs;

countCHs=0;

%counter for CHs per round

%rcountCHs=0;

countCHs;

flag_first_dead=0;

%throughput=zeros(rmax);

for i=1:1:n

davgbs=davgbs+S(i).d;

end

dvgbs=davgbs/n;

z=0;%total dead nodes

%sum=zeros(1,rmax);

for r1=1:1:rmax

r1

temp_rn=rand;

%sum=0;

%t initialised to zero after every round

t=0;

%Operation for epoch

if(mod(r1, round(1/prob) )==0)

for i=1:1:n

S(i).G=0;

S(i).cl=0;

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 Base 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(r1)=0;

PACKETS_TO_BS(r1)=0;

%initialising countCHs to 0 per round

countCHs = 0;

figure(1);

for i=1:1:n

if (S(i).d<do)

S(i).E=S(i).E- ( (Eelec)*(l) + Emp*l*( d*d));

%Energy_disp(r1)=Energy_disp(r1)+(Eelec)*(l) + Emp*l*( d*d);

%S(i).E=S(i).E- ( (ETX+EDA)*(4000) + Emp*4000*( distance*distance*distance*distance ));

end

if (S(i).d>=do)

S(i).E=S(i).E- ( (ETX+EDA)*(4000) + Efs*4000*( d * d * d * d ));

% Energy_disp(r1)=Energy_disp(r1)+(ETX+EDA)*(4000) + Efs*4000*( d * d * d * d );

%S(i).E=S(i).E- ( (ETX+EDA)*(4000) + Efs*4000*( distance * distance ));

end

%checking if there is a dead node

if (S(i).E<=0)

plot(S(i).xd,S(i).yd,'^','LineWidth',1, 'MarkerEdgeColor','k', 'MarkerFaceColor','y', 'MarkerSize',8);

dead=dead+1;%dead nodes per round

z=z+1;%total dead nodes

S(i).E=0;

S(i).type='d';

if (dead==1 && z==1)

if(flag_first_dead==0)

fd=r1;

flag_first_dead=1;

end

end

if(S(i).E==1)

dead_a=dead_a+1;

end

if(z==0.5*n)

if(flag_hd==0)

hd1=r1;

flag_hd=1;

end

end

if(S(i).E==0)

dead_n=dead_n+1;

end

hold on;

end

if(z==n)

if(flag_ad==0)

flag_ad=1;

ad1=r1;

end

end

if S(i).E>0

n_alive=n_alive+1;

S(i).type='N';

if (S(i).E==0)

plot(S(i).xd,S(i).yd,'s','LineWidth',1, 'MarkerEdgeColor','k', 'MarkerFaceColor','g', 'MarkerSize',8);

end

if (S(i).E==1)

plot(S(i).xd,S(i).yd,'+','LineWidth',3, 'MarkerEdgeColor','k', 'MarkerFaceColor','r', 'MarkerSize',8);

% ask Shreyas about this

end

hold on;

end

end

%plot(S(n+1).xd,S(n+1).yd,'x','LineWidth',1, 'MarkerEdgeColor','k', 'MarkerFaceColor','r', 'MarkerSize',8);

STATISTIC(r1).DEAD=dead;

%DEAD(r1)=dead;

DEAD_N(r1)=dead_n;

DEAD_A(r1)=dead_a;

% plot(S(n+1).xd,S(n+1).yd,'o', 'MarkerSize', 12, 'MarkerFaceColor', 'r');

% plot(S(n+1).xd,S(n+1).yd,'x','LineWidth',1, 'MarkerEdgeColor','k', 'MarkerFaceColor','r', 'MarkerSize',8);

%When the first node dies

countCHs=0;

cluster=1;

for i=1:1:n

if(S(i).E>0)

temp_rand=rand;

t=t+1;

if ( (S(i).G)<=0)

%if the G value is -ve

%Election of Cluster Heads according to the flowchart given in the paper

if(S(i).type~='d')

if(t<k && countCHs<k)

if(t>0)

while(rcountCHs(r1)<t)

% if(S(i).type=='A')

rcountCHs(r1)=rcountCHs(r1)+1;

packets_TO_BS=packets_TO_BS+1;

PACKETS_TO_BS(r1)=packets_TO_BS;

cluster=cluster+1;

plot(S(i).xd,S(i).yd,'dr');%plots cluster heads with red diamonds

S(i).type='C';

S(i).G=round(1/prob)-1;

C(cluster).xd=S(i).xd;

C(cluster).yd=S(i).yd;

d=sqrt( (S(i).xd-(S(n+1).xd) )^2 + (S(i).yd-(S(n+1).yd) )^2 );

C(cluster).distance=d;

C(cluster).id=i;

X(cluster)=S(i).xd;

Y(cluster)=S(i).yd;

%end

end

%ask help in implementing this flowchart-selection of cluster heads

if(t==0 & S(i).type~='C')

S(i).G=round(1/p)-1;

cluster=cluster+1;

end

%electing k-t cluster heads

while(rcountCHs(r1)<k-t)

rcountCHs(r1)=rcountCHs(r1)+1;

packets_TO_BS=packets_TO_BS+1;

PACKETS_TO_BS(r1)=packets_TO_BS;

S(i).type='C';

S(i).G=round(1/prob)-1;

cluster=cluster+1;

C(cluster).xd=S(i).xd;

C(cluster).yd=S(i).yd;

plot(S(i).xd,S(i).yd,'dr');

d=sqrt( (S(i).xd-(S(n+1).xd) )^2 + (S(i).yd-(S(n+1).yd) )^2 );

C(cluster).distance=d;

C(cluster).id=i;

X(cluster)=S(i).xd;

Y(cluster)=S(i).yd;

end

end

else

while(rcountCHs(r1)<t)

rcountCHs(r1)=rcountCHs(r1)+1;

packets_TO_BS=packets_TO_BS+1;

PACKETS_TO_BS(r1)=packets_TO_BS;

S(i).type='C';

S(i).G=round(1/p)-1;%UPDATING THE G VALUES OF THE NODES

cluster=cluster+1;

plot(S(i).xd,S(i).yd,'dr');%plots cluster heads with red diamonds

C(cluster).xd=S(i).xd;

C(cluster).yd=S(i).yd;

%plot(S(i).xd,S(i).yd,'k*');

d=sqrt( (S(i).xd-(S(n+1).xd) )^2 + (S(i).yd-(S(n+1).yd) )^2 );

C(cluster).distance=d;

C(cluster).id=i;

X(cluster)=S(i).xd;

Y(cluster)=S(i).yd;

end

%rcountCHs(r1)=rcountCHs+countCHs;

%plot(r,countCHs);

%Calculation of Energy dissipated & residual energy according to the energy

%equations in the paper from the helper nodes to the CH

for iter=1:1:4

if (h(iter).d<do)

S(i).E=S(i).E- ( (Eelec)*(l) + Emp*l*( d*d));

%Energy_disp(r1)=Energy_disp(r1)+(Eelec)*(l) + Emp*l*( d*d);

%S(i).E=S(i).E- ( (ETX+EDA)*(4000) + Emp*4000*( distance*distance*distance*distance ));

end

if (h(iter).d>=do)

S(i).E=S(i).E- ( (ETX+EDA)*(4000) + Efs*4000*( d * d * d * d ));

% Energy_disp(r1)=Energy_disp(r1)+(ETX+EDA)*(4000) + Efs*4000*( d * d * d * d );

%S(i).E=S(i).E- ( (ETX+EDA)*(4000) + Efs*4000*( distance * distance ));

end

end

end

end

end

end

if(S(i).E<0)

rcountCHs(r1)=0;

end

end

STATISTIC(r1).CLUSTERHEADS=cluster-1;

CLUSTERHS(r1)=cluster-1;

%Election of Associated Cluster Head for Normal Nodes

for i=1:1:n

if ( S(i).type=='N' & S(i).E>0 )

if(cluster-1>=1)

min_dis=sqrt( (S(i).xd-S(n+1).xd)^2 + (S(i).yd-S(n+1).yd)^2 );

min_dis_cluster=1;

for c=1:1:cluster-1

temp=min(min_dis,sqrt( (S(i).xd-C(c).xd)^2 + (S(i).yd-C(c).yd)^2 ) );

if ( temp<min_dis )

min_dis=temp;

min_dis_cluster=c;

end

end

% figure(4);

% title('Count of cluster heads per round');

% xlabel('round');

% ylabel('count of cluster heads');

% plot(r,countCHs);

%Energy dissipated by associated Cluster Head

if(min_dis_cluster~=0)

min_dis;

if (min_dis>do)

S(i).E=S(i).E- ( ETX*(l) + Efs*l*( min_dis * min_dis));

end

if (min_dis<=do)

S(i).E=S(i).E- ( ETX*(l) + Emp*4000*( min_dis * min_dis * min_dis * min_dis));

end

S(C(min_dis_cluster).id).E = S(C(min_dis_cluster).id).E- ( (ERX + EDA)*4000 );

packets_TO_CH=packets_TO_CH+1;

%Energy dissipated

if(min_dis>0)

d=sqrt( (S(C(min_dis_cluster).id).xd-(S(n+1).xd) )^2 + (S(C(min_dis_cluster).id).yd-(S(n+1).yd) )^2 );

S(C(min_dis_cluster).id).E = S(C(min_dis_cluster).id).E- ( (ERX + EDA)*4000 );

if (d>do)

S(C(min_dis_cluster).id).E=S(C(min_dis_cluster).id).E- ( (ETX+EDA)*(4000) + Emp*4000*( d*d*d*d ));

end

if (d<=do)

S(C(min_dis_cluster).id).E=S(C(min_dis_cluster).id).E- ( (ETX+EDA)*(4000) + Efs*4000*( d * d ));

end

PACKETS_TO_CH(r1)=packets_TO_CH;

end

S(i).min_dis=min_dis;

S(i).min_dis_cluster=min_dis_cluster;

end

end

end

end

hold on;

countCHs;

rcountCHs=rcountCHs+countCHs;

sum=0;

for i=1:1:n

if(S(i).E>0)

sum=sum+S(i).E;

end

end

avg=sum/n-Eo;

average(r1)=avg;

Even when I remove the avg variable & do sum/n-Eo directly the error persists. I am at my wits end. what to do? how do I get rid of this error?

Scalars being assigned to array elements is nothing new. why an error for this? What does the error message exactly mean "left & right side have a different number of elements"in terms of the error I'm getting? Kindly shed some light on what seems to be so dark.

[Jan]

Seriously?

So why is it giving me an arror in the line : average=avg

This line does not occur in your code. You have provided a huge piece of code. Because you did not spend the time to format the code (don't you see, that other questions use a nice formtiing?), therefore the code is not easy to read. I tried the search function of tzhe browser, but cannot find "average=avg".

Narrow down the problem. Post the relevant part of the code only and a copy of the complete error message. Do not let the readers guess, where the problem occurs and apply a proper formatting and code indentation. This will increase your chance to get an answer here.

Shadowing built-in functions causes troubles frequently. So do not overwrite "sum" by a variable. By the way:

sum=0;
for i=1:1:n
  if(S(i).E>0)
    sum=sum+S(i).E;
  end
end

can be abbreviated to:

value = [S.E];
ESum  = sum(value(value > 0));

Writing code without useful comments is a waste of time, because this impedes the debugging massively. Neither the readers in the forum, not you in 3 month, will understand the purpose of the code, if you do not clarify this explicitly in comments.

[Guillaume]

+1 to everything Jan said.

[Image Analyst]

Just attach the actual m-file with the paper clip icon. Then delete all the code from your answer (it's no good anyway according to Jan), or else format it by highlighting and clicking the Code icon Code can be indented properly in the MATLAB editor by typing control-a control-i.

Then if you still have errors after fixing the sum variable name problem Jan pointed out, give us ALL THE RED TEXT, which includes the line of text, the line number, etc. Not just a snippet of the red text but ALL of it.