subplot(3,1,1)
plot(t,V,'p')

subplot(3,1,2)
semilogy(t, V,'o')

subplot(3,1,3)
loglog(t, V,'s')

logV=log(V);
plot(t, logV, 'p')
xlabel time(s)

% use basic fitting interface to fit 
% start interface from the tools menu 
% select linear and show equation 

B = 4.58;
m = - 0.988;
b=exp(B);
Vhat = b*exp(m*t);
plot(t, V, 'o', t, Vhat)

