p_dot.f

Go to the documentation of this file.

!                   *******************************
                    DOUBLE PRECISION FUNCTION p_dot
!                   *******************************
!
     &(npoin,x,y,ifac)
!
!***********************************************************************
! BIEF   V7P1
!***********************************************************************
!
!brief    SCALAR PRODUCT OF VECTORS X AND Y (SIZE NPOIN)
!+                TAKING PARALLELISM INTO ACCOUNT.
!
!history  REINHARD HINKELMANN (HANNOVER UNI.)
!+
!+
!+
!
!history  N.DURAND (HRW), S.E.BOURBAN (HRW)
!+        13/07/2010
!+        V6P0
!+   Translation of French comments within the FORTRAN sources into
!+   English comments
!
!history  N.DURAND (HRW), S.E.BOURBAN (HRW)
!+        21/08/2010
!+        V6P0
!+   Creation of DOXYGEN tags for automated documentation and
!+   cross-referencing of the FORTRAN sources
!
!history  J-M HERVOUET (EDF LAB, LNHE)
!+        10/06/2015
!+        V7P1
!+   Moving from double precision FAC to integer IFAC.
!
!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
!| FAC            |-->| FAC=1/(NUMBER OF NEIGHBOURING SUB-DOMAINS)
!| NPOIN          |-->| SIZE OF X AND Y
!| X              |-->| VECTOR
!| Y              |-->| VECTOR
!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
!
      USE bief, ex_p_dot => p_dot
!
      USE declarations_special
      IMPLICIT NONE
!
!+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
!
      INTEGER, INTENT(IN) :: NPOIN
!
      DOUBLE PRECISION, INTENT(IN) :: X(npoin),Y(npoin)
      INTEGER, INTENT(IN)          :: IFAC(npoin)
!
!+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
!
      INTEGER I
!
!-----------------------------------------------------------------------
!
      p_dot = 0.d0
!
      DO i = 1 , npoin
        p_dot = p_dot + x(i) * y(i) * ifac(i)
      ENDDO
!
!-----------------------------------------------------------------------
!
      RETURN
      END