49 lines
1005 B
FortranFixed
49 lines
1005 B
FortranFixed
|
c****************************************************************
|
||
|
|
|
||
|
|
subroutine unitvec(r_v,r_u)
|
||
|
|
|
||
|
|
c****************************************************************
|
||
|
|
c**
|
||
|
|
c** FILE NAME: unitvec.f
|
||
|
|
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
|
||
|
|
|