dbcsr_get_local_vcols Subroutine

   SUBROUTINE dbcsr_get_local_vcols(imgdist, local_vcols, local_vpcol)
      !! Determines mapping from local to global virtual process columns

      TYPE(dbcsr_imagedistribution_obj), INTENT(INOUT)   :: imgdist
         !! image distribution
      TYPE(array_i1d_obj), INTENT(OUT)                   :: local_vcols
         !! local columns
      INTEGER, INTENT(IN)                                :: local_vpcol
         !! the local virtual process column

      CHARACTER(len=*), PARAMETER :: routineN = 'dbcsr_get_local_vcols'

      INTEGER                                            :: el, error_handle, nvpcols, vpcol
      INTEGER, ALLOCATABLE, DIMENSION(:)                 :: nle
      INTEGER, DIMENSION(:), POINTER                     :: itmp, vcol_dist

      IF (careful_mod) CALL timeset(routineN, error_handle)
      ! If the current local col mappings do not exist, create them.
      IF (.NOT. imgdist%i%has_other_vl_cols) THEN
         imgdist%i%has_other_vl_cols = .TRUE.
         nvpcols = dbcsr_mp_npcols(dbcsr_distribution_mp(imgdist%i%main)) &
                   *imgdist%i%col_decimation
         ALLOCATE (imgdist%i%other_vl_cols(0:nvpcols - 1))
         ALLOCATE (nle(0:nvpcols - 1))
         vcol_dist => array_data(imgdist%i%vcol_dist)
         ! Count the number of local elements per col.
         nle(:) = 0
         DO el = 1, SIZE(vcol_dist)
            vpcol = vcol_dist(el)
            nle(vpcol) = nle(vpcol) + 1
         END DO
         DO vpcol = 0, nvpcols - 1
            ALLOCATE (itmp(nle(vpcol)))
            itmp = 0
            CALL array_new(imgdist%i%other_vl_cols(vpcol), &
                           itmp, lb=1)
            DEALLOCATE (itmp)
         END DO
         DEALLOCATE (nle)
         CALL find_all_local_elements(imgdist%i%other_vl_cols, vcol_dist, nvpcols)
      ELSE
         IF (careful_mod .AND. .NOT. ASSOCIATED(imgdist%i%other_vl_cols)) &
            DBCSR_ABORT("Local cols mapping does not exist.")
      END IF
      local_vcols = imgdist%i%other_vl_cols(local_vpcol)
      IF (careful_mod) CALL timestop(error_handle)
   END SUBROUTINE dbcsr_get_local_vcols