%
%   plot the drops from the pier
%
load exp_23_25.txyz
t=exp_23_25(100:32768,1);
ax=exp_23_25(100:32768,2);
ax=ax-mean(ax);
ay=exp_23_25(100:32768,3);
ay=ay-mean(ay);
az=exp_23_25(100:32768,4);
az=az-mean(az);
a=sqrt(ax.*ax+ay.*ay+az.*az);
%
%  plot the whole time series
%
figure(1)
clf
subplot(3,1,1);plot(t,ax);ylabel('ax');axis([0,250,-15,15]);
subplot(3,1,2);plot(t,ay);ylabel('ay');axis([0,250,-15,15]);
subplot(3,1,3);plot(t,az);ylabel('az');xlabel('time');axis([0,250,-15,15]);
% 
%  zoom in on some data
%
figure(2)
clf
t1=t(1400:3000);
a1=az(1400:3000);
plot(t1,a1),;ylabel('az');xlabel('time(s)')
%
%   look at the power spectrum of the whole time series
%
figure(3)
clf
Fs=128;
h=spectrum.welch;
Hpsd = psd(h,az,'Fs',Fs);
plot(Hpsd);xlabel('frequency (Hz)');ylabel('power')
%axis([0,20,-30,20])
