Synopsis
		sfstoltstretch < in.rsf > st.rsf velocity=vel.rsf inv=n nstretch=1 pad=nt eps=0.01 vel=

Parameters
		float eps=0.01 stretch regularization   bool inv=n [y/n] if y, inverse stretch   int nstretch=1 number of steps   int pad=nt time axis padding   float vel= reference velocity   file velocity= auxiliary input file name