Ploblem in calculating Coherence using csd funtion

I have two time series data f1 and f2 having a period of 12hours datagap for which I wish to calculate coherence.

I have downloaded the function called func_coherence from the MATLAB Central which you have written and fed my data to it. The value coherence I am getting is 1 for all the periodicities, whereas I am seeing a strong 48h peak in Pxx, Pyy and also in Pxy.

I am attaching my data to you. to check. Please kindly help me.

F1=[ 2.4938  8.7676  2.2365  4.0216  9.2297  4.4414  1.5466  0.1564  5.9694  -2.5503   0.1252  -0.8798   4.2279  -3.4285  -5.6145   3.8539  8.3706   2.0150  -5.2399  -8.0904];
F2=[ 2.0103  3.9944  6.0057  3.3494  3.3044  6.4753  3.0004  2.1443  2.1656   0.3363  -3.1703  -1.9084  -0.5694   1.0629  -1.1216  -7.2866  3.4947  11.4590   5.0680   1.6860];

% % % Syntax [ Pxx, Pyy, Pxy, coh, pha, freq ] = func_coherence( f1, f2, nfft, Fs, filt, n_overlap )

% [Pxx,Pyy,Pxy,coh,pha,freq ] = func_coherence(F1,F2, [],1./12, [], [] );

[Pxx,freq] = csd( F1, F1, [],1./12, [], [] );
[Pyy,freq] = csd( F2, F2, [],1./12, [], [] );
[Pxy,freq] = csd( F1, F2, [],1./12, [], [] );

Kxy  = real( Pxy );
Qxy  = imag( Pxy );
coh  = Pxy.*conj(Pxy)./(Pxx.*Pyy);
pha  = mod(atan2( Qxy, Kxy ).*180/pi,360);
cix=ci(coh',95);
ts=1./freq;

Subplot(321),plot(ts,Pxx);title('P_x_x');axis tight;
Subplot(322),plot(ts,Pyy);title('P_y_y');axis tight;
Subplot(323),plot(ts,Pxy);title('P_x_y');axis tight;
Subplot(324),plot(ts,coh,ts,cix,'r');title('Coherence');axis tight;
Subplot(325),plot(ts,pha);title('Phase');axis tight;

Answer 1

[toolmotor beartiger]

What is the ci?