Program sfvam | Create a layered model. 
[SYNOPSIS]
sfvam > vfile.rsf nz= nx= dz= dx=
[PARAMETERS]
float   | dx | = |   | 	distance sampling 
float   | dz | = |   | 	depth sampling 
int     | nx | = |   | 	distance grid 
int     | nz | = |   | 	depth grid 
[DIRECTORY]
user/hpcss
