why do I have this error in index

Hello Can anyone help me please I have this error in matlab in plotting

 Error in prob (line 13)
 Vc1(i)= f1(indx(i));

So can anyone help me

you can see my code

clear all;
indx=[0.0:4.99:50.0];

f1=@(x) Ceoscj(4,p);
f2=@(x) Cesow(4,p);
f3=@(x) Oscj(4,p);
f4=@(x) Swb(4,p);
f5=@(x) Ssj(4,p);

for i=1:size(indx,2)

   Vc1(i)= f1(indx(i));
   Vc2(i)= f2(indx(i));
   Vc3(i)= f3(indx(i));
   Vc4(i)= f4(indx(i));
   Vc5(i)= f5(indx(i));

end
plot(indx,Vc1,'-o');

hold on;
plot(indx,Vc2,'-*');

hold on;
plot(indx,Vc3,'-s');
hold on;
plot(indx,Vc4,'-d');
hold on;
plot(indx,Vc5,'-m');

hold on;
leg=legend('Cesosj','Cesow','Oscj','Ssj');
set(leg,'location','best')
set(gca,'XTick',(0:5:50))
set(gca,'YTick',(0:10^-1:10^0))
xlabel('P [dB]');
ylabel('Secrecy Outage Probability');

thanks in advance

[Stephen23]

@lakom Mariem: please show us the complete error message. That means all of the red text.

[lakom Mariem]

Error in @(x)Ceoscj(4,p)

Error in prob (line 13) Vc1(i)= f1(indx(i));

[Jan]

@lakom Mariem: Are you really sure that this is the complete message? It tells only, where the error occurs, but not, what the problem is. This is really unusual for error messages in Matlab.

Answer 1

[Star Strider]

You didn’t say what the error is, although I am guessing that it is ‘Undefined function or variable 'p'.’.

Note that here:

f1=@(x) Ceoscj(4,p);

the argument to ‘f1’ is ‘x’, and does not refer to ‘p’ (that is apparently undefined in your code).

[Jan]

@lakom Mariem: The p must be undefined after the clear all.

Answer 2

[OCDER]

You are accessing a matrix using a non-integer index right here, which is not allowed. Index must be an integer > 0. Another issue is that your function handle uses 'x' as a variable, but you have 'p' instead. See comments below:

indx=[0.0:4.99:50.0];   %your index is not an integer > 0. What is the 0th element of a vector?
f1=@(x) Ceoscj(4,p);    %variable is x, but you use p. To fix, use: f1 = @(x) Ceoscj(4,x)
for i=1:size(indx,2)    %use numel.  for i = 1:numel(indx)
   Vc1(i)= f1(indx(i)); %here, f1(indx(1)) = f1(0). What is the 0th element of f1?
                        %Also, you do not preallocate Vc1, meaning this will be slow due to
                        % matrix creation, deletion, and copying every time the size changes in a loop.
end
plot(indx,Vc1,'-o');    %indx is used only as a x value, so maybe rename indx to x. 
                        % Your "i" in the for loop counter is the real "index" variable.

Using all these loops and function handles is quite hard to maintain in the long run. I would instead try to make your functions like Ceoscj take in a vector input x and return a vector output. That way, you could do something like this:

x =[0.0:4.99:50.0];   
Vc1 = Ceoscj(4, x);
plot(x, yVc1)