I can't plot during my loop! Help!

if true
  disp('Question 3')
nMAX = input('Enter nMAX');
sumX=0;
i=1;
while i<=nMAX
 plot(i,sumX); hold on
 sumX = sumX + 1/i^2;
 i=i+1; 
end
disp('The sum of the series is');
disp(sumX);
disp('END Question 3');
end

The above is my code, when I try to plot, nothing appears. Im new to matlab so go easy lol. I would like to put sumx against i for 1:50. Thanks.

Answer 1

[Konstantinos Sofos]

Hi you could use

plot(i,sumX,'k*'); % set black asterisk

[Bikram Singh]

Hi, thanks it does work.... but could you explain why that works and is there a way to just make the plot a line rather than a set of points?

[Konstantinos Sofos]

To make a line you need to have vectors...in your case you give just points...one possibility would be

if true
    disp('Question 3')
    nMAX = input('Enter nMAX : ');
    sumX=0;
    for i = 1 : nMAX -1
        sumX(i+1) = sumX(i) + 1/i^2;    
    end
    plot(1:nMAX,sumX);
    disp('The sum of the series is');
    disp(sumX(end));
    disp('END Question 3');
end

[Bikram Singh]

So, how would I adjust the code to make this happen? Sorry, very new to Matlab.

[Walter Roberson]

That is the adjusted code that Konstantinos posted.