Synopsis
		sfduffing2 < cmp.rsf > outf.rsf restor=restor.rsf winsz=200 v0=1000 dv=20 vn=100 t0=o1 deltat0=dt t0n=n1 gamma=0.75 omega=1 kxi=1 x0=0 y0=0 pow1=1 pow2=3 phi=0. cosine=y delta=0.01 verb=n gx=2.0

Duffing equation: x''/(omega^2)+0.5 x'/omega-x+x^3=gamma cos(omega t+phi)+kxi R(t)

Parameters
		bool cosine=y [y/n] if n need extenal input for periodic restoring force   float delta=0.01 The density of judgement grid   float deltat0=dt step lenth for t0 scan   float dv=20 step lenth for velocity scan   float gamma=0.75 strength of external force   float gx=2.0 Size of grid   float kxi=1 adjustment for input signal   float omega=1 angular frequence of external force   float phi=0. phase of cosine signal unit=pi   int pow1=1 power of first non-linear restitution term   int pow2=3 power of second non-linear restitution term   string restor= auxiliary input file name   float t0=o1 t0 scan start point   int t0n=n1 numbers of t0scan   float v0=1000 init Vel for velocity scan   bool verb=n [y/n] verbosity flag   int vn=100 numbers of velscan   int winsz=200 for each trace,the width of window. Unit:samples   float x0=0 initial value of x0   float y0=0 initial value of y0