Program sfanalytical | First-arrival traveltime table using analytical traveltimes 
[SYNOPSIS]
sfanalytical < in.rsf > out.rsf vel=y order=3 yshot=x0 + 0.5*(nx-1)*dx zshot=z0
[PARAMETERS]
int     | order | =3 |   | 	interpolation accuracy for velocity 
bool    | vel | =y |  [y/n] | 	y, input is velocity; n, slowness 
float   | yshot | =x0 + 0.5*(nx-1)*dx |   | 	
float   | zshot | =z0 |   | 	read velocity or slowness 
[DIRECTORY]
user/fomels
