## Triangle_wave question

### Qingchuan Lyu (view profile)

on 29 Jun 2018
Latest activity Answered by Star Strider

### Star Strider (view profile)

on 29 Jun 2018 In this question, I have used the debugging tool in matlab and checked step by step. Everything looks fine. However, when I test my codes in the whole, everything seems broken. Could someone give me a hint how to fix my codes? Previously, someone has posted his codes for the same question, but my codes do not have the same issues. In particular, when n=10, the first element of v should be 0, but i got something different. The weird thing is that i did get 0 when debugging.
if true
% function v = triangle_wave(n)
me=zeros(1,n+1);
v=zeros(1,1001);
for t = 0:4*pi
for i=1:1001
for k = 0:n
me(k+1) = ((-1).^k)*sin(2.*k.*t+t)./(2.*k+1).^2;
end
v(i)=sum(me);
k = k+1;
t=t+4*pi/1000;
i=i+1;
end
end
end

### Products ### Star Strider (view profile)

on 29 Jun 2018

You have coded the essential loop correctly. The problem is that you overloaded your code with a lot of irrelevant items. I would increase the resolution of ‘t’, and simply use the ‘k’ loop:
t = linspace(0,4*pi);
n = 100;
me = zeros(n+1, numel(t));
for k = 0:n
me(k+1,:) = ((-1).^k)*sin(2.*k.*t+t)./(2.*k+1).^2;
end
me = sum(me);
figure
plot(t, me)
The plot is not necessary for the code. It simply shows the result.
Experiment to get the result you want.