Program sfvoft | V(t) function for a linear V(Z) profile.
[SYNOPSIS]
sfvoft < in.rsf > out.rsf v0=1.5 alpha=0.5
[PARAMETERS]
float   | alpha | =0.5 |   | 	velocity gradient 
float   | v0 | =1.5 |   | 	initial velocity 
[DIRECTORY]
system/seismic
