function [Ck,fk] = DFTCmplx( T,F )
%UNTITLED2 Summary of this function goes here
% Detailed explanation goes here
N=length(F)/2; dt=(T(2*N)-T(1))/(2*N-1);
fk=[0:N]/(dt*2*N); Ck(1)=sum(F(1:2*N))/(2*N);
for k=2:N
CkI(k)=0; CkR(k)=0;
for j=1:2*N
CkI(k)=CkI(k)+F(j)*sin(pi*(k-1)*T(j)/(dt*N));
CkR(k)=CkR(k)+F(j)*cos(pi*(k-1)*T(j)/(dt*N));
end
Ck(k)=(CkR(k)-CkI(k)*i)/(2*N);
end
Ck(N+1)=0;
for j=1:2*N
Ck(N+1)=Ck(N+1)+F(j)*cos(pi*N*T(j)/(dt*N));
end
Ck(N+1)=Ck(N+1)/(4*N);
end
nu = 200; Frq=200;
Fun = @ (t) sin(2*pi*Frq*t)+0.5*sin(2*pi*4*Frq*t)+0.8*cos(2*pi*2*Frq*t)
+0.4*cos(2*pi*12*Frq*t);
fS = 20000; dts = 1/fS; tau = 0.005;
tp = linspace(0,tau,200);
yp = Fun (tp) ;
ts = 0:dts:tau-dts;
ys = Fun (ts) ;
plot(tp*1000,yp, 'k' ,ts*1000,ys,'oc')
[C fr] = DFTCmplx(ts,ys);
figure;
stem(fr,real(C) ,'oc' ,'markersize' ,12,'LineWidth' ,1)
figure
stem(fr,imag(C) ,'oc', 'markersize' ,12, 'linewidth' ,1)
A=real(2i*C); B=imag(2i*C);
figure;
stem(fr,A ,'or' ,'markersize' ,12,'LineWidth' ,1);
figure;
stem(fr,B ,'or' ,'markersize' ,12,'LineWidth' ,1);
