!c*****************************************************************

	subroutine unitvec(r_v,r_u)

!c****************************************************************
!c**
!c**	FILE NAME: unitvec.for
!c**
!c**     DATE WRITTEN: 8/3/90
!c**
!c**     PROGRAMMER:Scott Hensley
!c**
!c** 	FUNCTIONAL DESCRIPTION: The subroutine takes vector and returns 
!c**     a unit vector.
!c**
!c**     ROUTINES CALLED:none
!c**  
!c**     NOTES: none
!c**
!c**     UPDATE LOG:
!c**
!c*****************************************************************

       	implicit none

!c	INPUT VARIABLES:
        real*8 r_v(3)                              !3x1 vector
   
!c   	OUTPUT VARIABLES:
        real*8 r_u(3)                              !3x1 vector

!c	LOCAL VARIABLES:
	real*8 r_n

!c  	PROCESSING STEPS:

!c       compute vector norm

        r_n = sqrt(r_v(1)**2 + r_v(2)**2 + r_v(3)**2)
      
        if(r_n .ne. 0)then  
          r_u(1) = r_v(1)/r_n
          r_u(2) = r_v(2)/r_n
          r_u(3) = r_v(3)/r_n
        endif
 
        end