how to plot a summation function in matlab using a for loop

how can i plot this summation function using a for loop?

i start write this:

t = -pi : pi/6 : pi;

s=0;

for i = 0:1

s=s+(2/3)*(pi^2) + ((-1)^i)* (-4*cos(i*t))/i^2

Answer 1

[Rik]

It's a good start.

You should only put the summation part in the loop, and you should store the results in a vector. (remember that the first element of a vector is index 1)

I would also suggest that you use n instead of i.

If you need help implementing this, feel free to post a comment.

[Dimitra]

Thank you very much!!

Yes, can you please help me, because it seems difficult for me

e.g. I would like to plot it for n=2

[Dimitra]

I run the my code , and the figure is empty

[Rik]

The code you sent me by email is the exact same you posted in your original question. Why didn't you try to implement my advice?

Also, the code you posted will not result in a figure at all, so you didn't show all the code you're using. Neither of these two things are an effective way to solve the problem.

Please post your full code and format it properly. That way you can run it immediately in the editor.

[Rik]

I understand it may be difficult to ignore the spammer, but feel free to follow up with a comment.

Answer 2

[Torsten]

For reference:

syms k t
f(t) = 4*symsum((-1)^(k+1)*cos(k*t)/k^2,k,1,Inf)

f(t) = 

f(0)

ans = 

fplot(f+2/3*pi^2,[-2*pi,2*pi])