Plotting only one data point

Hello im trying to do a plot but its only plotting one data point.

The code is:

    Xei_1 = Xei;
        Er = abs((Xei - Xei_1)/Xei_1)*100;% calculating Relative Error
        
        plot(i,Er,'-o'); % plotting iterations and relative % errors 
        xlim([1,imax]); 
        ylim([0,100]); 
        xlabel('Iteration');
        ylabel('Relative % Error')
        grid on
        

Answer 1

[KSSV]

It looks like you are running a loop. Follow like shown below:

N = 100;   % loop count 
Er = zeros(1,N) ; 
for i = 1:N
      Xei_1 = Xe(i);
     Er(i) = abs((Xei - Xei_1)/Xei_1)*100;% calculating Relative Error
end
plot(1:N,Er)

Also you can vectorise the lines depending on what your code is.