% Jhosc(p,f). The creep function of the harmonic oscillator consisting of 
% R,L,C in series. p=[f0,q], f0=1/(2*pi*sqrt(L C)) resonance frequency, q=sqrt(L/C)/R, quality factor 
function J=Jhosc(p,f)
f0=p(1);q=p(2);x=f/f0;
J=1./(1-x.*x+i*x/q);