MATLAB: Boucle for add the element behind

Question

i want to add teh element behind for exemple when i =3

i want to add the element when i=1 to i=3 and plot it evry time till the i=9

so for i=9 –> means you add evry thing in the back i=1 i=3 i=5 i=7

f=1;
T=1/f;
t=-1:T/300:1;
sq=1*square(2*pi*f*t);
figure
plot(t,sq)
hold on
for i=1:2:9
v=i+2
x_i=(4/(pi*i))*sin((2*pi*i*t));
x_v=((4/(pi*v))*sin((2*pi*v*t)));
r=x_i+x_v;
plot (t,r);
hold on
end

Answer 1

doc cumsum