Stuff here is to get geometical information inside a 
gvien detector by using a neutrino as the incident 
partcile.
The program responsible for the work is epGeom.f;
its ingredients are called from ephook.f
Execpt for that the primary is neu_e and optional
2 control parameters given inside "sepicsfile",
there is no special points.
  Suupose a newtrino passes thru  many componests
  we see it runs in many different media. The path
  is devided into many segments, each of which consists
  of the same medium.  If medium changes or component
  number changes during the path, segment becomes different.
(see fig.pdf. The output format is also seen there)

Out of two control parameters in sepicsfile, 2nd one
neednot be touched. First one is to suppress blanks.
The default is no suppression;

 epHooks '0 2  0'       / Entry for giving user defined parametes.
 epHooki  0  /  0-> no blank suppress. 1-> blank suppress
 epHooki  1 /   1->make pos world coord.   0-> pos.  local coord. (for debug)
