ISCE_INSAR/components/stdproc/orbit/orbitLib/src/dot.f90

44 lines
893 B
Fortran

!c****************************************************************
real*8 function dot(r_v,r_w)
!c****************************************************************
!c**
!c** FILE NAME: dot.f
!c**
!c** DATE WRITTEN:7/15/90
!c**
!c** PROGRAMMER:Scott Hensley
!c**
!c** FUNCTIONAL DESCRIPTION: This routine computes the dot product of
!c** two 3 vectors as a function.
!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),r_w(3) !3x1 vectors
!c OUTPUT VARIABLES: dot is the output
!c LOCAL VARIABLES:none
!c DATA STATEMENTS:none
!C FUNCTION STATEMENTS:none
!c PROCESSING STEPS:
!c compute dot product of two 3-vectors
dot = r_v(1)*r_w(1) + r_v(2)*r_w(2) + r_v(3)*r_w(3)
end