functions in drat.i - f

             boundary= find_boundary(mesh)  
          or boundary= find_boundary(mesh, region, sense)  
 
     returns an array of 4 pointers representing the boundary of the  
     MESH, or of a particular REGION of the MESH, with a particular  
     SENSE -- 0 for counterclockwise in the (r,z)-plane, 1 for  
     clockwise.  The returned arrays are:  
        *boundary(1)   zone index list -- always 1-origin values  
	*boundary(2)   side list 0, 1, 2, or 3  
                       side 0 is from point zone to zone-1, side 1 is  
                       from zone-1 to zone-imax-1  
	*boundary(3)   z values of boundary points  
	*boundary(4)   r values of boundary points  

builtin function, documented at i0/drat.i   line 1095  

             form_mesh(zsym, khold, lhold)  
 
     returns an opaque "mesh" object, which will hold rt, zt, ireg,  
     and a boundary edge list.  This opaque mesh object is required  
     as an input to the integ_flat and integ_linear routines.  
     ZSYM is 2 for spherical symmetry, 1 for z=0 reflection symmetry,  
          or 0 for no symmetry  
     KHOLD and LHOLD are the 1-origin indices of "hold" lines in the  
          mesh, or 0 if none.  This information is used only during the  
	  pcen_source operation before integ_linear is called.  

builtin function, documented at i0/drat.i   line 1071