| [Ahat,Theta,Omega,RMS]=sinefit(s0,Testim,t0,Ts)
|
% sine wave fitting from noisy sinusoidal signal
% phase fitting has to be considered as well as frequency
% Written by Dr Chen YangQuan <yqchen@ieee.org>
% Last modified 05-11-2000
% s0: sampled series. 1xNp
% Testim: estimated period (sec.) (may not be accurate)
% Ts: sampling period (in Sec.)
% t0: initial time (in Sec.)
% Ahat: estimated amplitude
% Theta: fitted theta_0 (in rad.)
% Omega: 2pi*freq
% RMS: root mean squares.
%
% See also: sinefit2
function [Ahat,Theta,Omega,RMS]=sinefit(s0,Testim,t0,Ts)
%
Omega=fmin('jomega',(2*pi/Testim)*.5,...
(2*pi/Testim)*2.0, [0,1.0e-30 ], s0,t0,Ts)
[Ahat,Theta,RMS]=sinefit2(s0,Omega,t0,Ts);
disp(['f=',num2str(Omega/2/pi),...
' | RMS=',num2str(RMS),' A ^ =', num2str(Ahat),...
' | Theta ^ =',num2str(Theta*180/pi)])
Np=size(s0);
t=t0+[0:Np(2)-1]*Ts;
figure;
plot(t,s0,'k:',t, Ahat*sin(Omega*t+Theta),'-r');
legend(['measured (RMS=',num2str(RMS),')'],...
['fitted: f=',num2str(Omega/2/pi),...
' A.hat =',num2str(Ahat),...
' | theta.hat =',num2str(Theta*180/pi)])
return |
|
