program SendArray
  use mpi
  implicit none
  integer ierr, me, nprocs, errcode, sndto,rcvfrom
  integer status(MPI_STATUS_SIZE)
  integer,parameter :: ndata = 10000
  real              :: a(ndata)
  real              :: b(ndata)

  call MPI_INIT(ierr)
  call MPI_COMM_SIZE(MPI_COMM_WORLD, nprocs, ierr)
  call MPI_COMM_RANK(MPI_COMM_WORLD, me, ierr)

  !$ Initialize data 
  a = me

!$ Send and Receive data    
  sndto = me+1; if ( sndto > nprocs-1 ) sndto=0
  rcvfrom = me-1; if ( rcvfrom < 0 ) rcvfrom=nprocs-1

  call MPI_SENDRECV(a,ndata,MPI_REAL,sndto,0,b,ndata,MPI_REAL,rcvfrom,0,MPI_COMM_WORLD,status,ierr)

  print *,'I am proc ',me,' and I have received b(1) = ',b(1)
!$ Finalize MPI
  call MPI_FINALIZE(ierr)

end program sendarray