55   vector< vector< vector< double > > > 
xField;
 
   56   vector< vector< vector< double > > > 
yField;
 
   57   vector< vector< vector< double > > > 
zField;
 
   61   double minx, maxx, miny, maxy, 
minz, maxz;
 
   69   void  GetFieldValue( 
const  double Point[4],
 
   70                        double *Bfield          ) 
const;
 
vector< vector< vector< double > > > xField
 
vector< vector< vector< double > > > zField
 
vector< vector< vector< double > > > yField