Need help plotting this

Hello, I don't know how to plot waves in matlab with fourier function. It should plot like this.

Here is the code

n = 36;

T=20*10^-3;

t=0:T/1000:T;

w=2*pi*1/T;

%f=i(t)

f=@(t)0+100.*(t>1*T/12).*(t<5*T/12)-100.*(t>7*T/12).*(t<11*T/12);

a0 = 2/T*integral(@(t)f(t),0,T);

for i=1:n

%a(i)=an

a(i) = 2/T*integral(@(t)f(t).*cos(w*i*t),0,T);

%b(i)=ab

b(i) = 2/T*integral(@(t)f(t).*sin(w*i*t),0,T); %until here the code works fine

%v(i)=vn

v(i)=atan(a(i)./b(i));

%r(i)=rn

r(i)=(a(i)./(sin(v(i))));

end

in=@(t) (r(1:n).*sin((1:n)*w*t+v(1:n)));

in_eval = arrayfun(in,t);

%plot column trace rn/r1*100

figure(5)

plot(t,in(n(1)),'DisplayName', 'in(1,t)')

hold on

plot(t,in(n(5)),'DisplayName', 'in(5,t)')

hold on

plot(t,in(n(7)),'DisplayName', 'in(7,t)')

xlabel('Time','FontSize',16)

title('3.12','FontSize',16)

The integral part of code is originated from here:

an and bn are matrix indexes

Answer 1

[Torsten]

n = 36;
T=20*10^-3;
t=0:T/1000:T;
w=2*pi*1/T;
%f=i(t)
f=@(t)0+100.*(t>1*T/12).*(t<5*T/12)-100.*(t>7*T/12).*(t<11*T/12);
a0 = 2/T*integral(@(t)f(t),0,T);  
for i=1:n
    %a(i)=an
    a(i) = 2/T*integral(@(t)f(t).*cos(w*i*t),0,T);
    %b(i)=ab
    b(i) = 2/T*integral(@(t)f(t).*sin(w*i*t),0,T);  %until here the code works fine
end
%v(i)=vn
v=atan(a./b);
%r(i)=rn
r=a./sin(v);
in=@(n,t) r(n)*sin(n*w*t+v(n));
%plot column trace rn/r1*100
figure(5)
plot(t,in(1,t),'DisplayName', 'in(1,t)')    
hold on
plot(t,in(5,t),'DisplayName', 'in(5,t)')
hold on
plot(t,in(7,t),'DisplayName', 'in(7,t)')
xlabel('Time','FontSize',16)
title('3.12','FontSize',16)

[Dani German]

Awesome, thanks for your help.