%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% OBTAIN  RECORD PARAMETERS:
%
% PGA, PGV, PGD
% PGV / PGA
% total duration
% significant duration
% Arias (Ia)
% Root-mean-square (RMS) of acceleration
% characteristic (Ic) intensities
% Cumulative Absolute Velocity (CAV)
% Spectral Intenstity SI (Housner)
%
% created by Michalis Fragiadakis, Dec 2013
% mfrag@mail.ntua.gr
%
% please report any bugs
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
includeFile

dt = acc.dtacc;
ac = acc.rec*9.81;
nsteps = acc.nsteps;

% Arias Intensity
arias=(pi/2/9.81)*(dt*cumtrapz(ac.*ac));

acc.Arias = max(arias);
husid = arias*100/acc.Arias;

% plot Fourier Amplitide Spectrum (FAS)
figure()
title('Husid plot','FontSize',22)
hold on; grid on; box on;
plot((1:nsteps)*dt,husid,'b-','LineWidth',3)
xlabel('time (sec)','FontSize',20)
ylabel('Husid (%)','FontSize',20)
set(gca,'FontSize',16)

%	Significant Duration:
time1 = max(find(husid < 5));
time2 = min(find(husid > 95));

plot([time1*dt,time2*dt],[husid(time1),husid(time2)],'r.','LineWidth',3,'MarkerSize',30)

acc.SignificantDuration = (time2-time1)*dt;

h = legend('husid plot','significant duration');
set(h,'Fontsize',16,'Location','SouthEast')


% total duration
acc.TotalDuration = nsteps*dt;

% rms acceleration:
acc.rms_acceleration_g =sqrt(acc.Arias*2.0*9.81/(nsteps*dt)/pi)/9.81;

% Characteristic Intensity:
acc.CharacteristicIntensity_Ic=((acc.rms_acceleration_g)^1.5)*(nsteps*dt)^0.5;

% Cumulative absolute velocity
acc.CumAbsoluteVelocity_CAV_cm = 100*max((dt*cumtrapz(abs(ac))));

% Spectral Intensity:
td=0.1:0.01:2.5;
for j=1:length(td)
    [umax(j),vmax(j),amax(j)]=sdfL(td(j),ac,0.05,dt,nsteps); % new signal
end;
acc.ResponseSpectrumIntensity_SI_cm=100*(max(0.01*cumtrapz(abs(vmax))));


vel = dt*cumtrapz(ac);
dis = dt*cumtrapz(vel);

pgd  = max(abs(dis));
pgv  = max(abs(vel));
pga  = max(abs(ac));

acc.pga = pga;
acc.pgv = pgv;
acc.pgd = pgd;

acc.VoverA=pgv/pga;

acc