dbcsr_triu Subroutine

public subroutine dbcsr_triu(matrix_a)

triu of a dbcsr matrix

Arguments

TypeIntentOptionalAttributesName
type(dbcsr_type), intent(inout) :: matrix_a

the matrix


Contents

Source Code


Source Code

   SUBROUTINE dbcsr_triu(matrix_a)
      !! triu of a dbcsr matrix

      TYPE(dbcsr_type), INTENT(INOUT)                    :: matrix_a
         !! the matrix

      CHARACTER(len=*), PARAMETER :: routineN = 'dbcsr_triu'
      INTEGER                                            :: blk, blk_nze, col, col_size, handle, i, &
                                                            j, row, row_size
      LOGICAL                                            :: tr
      REAL(dp), DIMENSION(:, :), POINTER                 :: DATA
      TYPE(dbcsr_iterator)                               :: iter

!   ---------------------------------------------------------------------------

      CALL timeset(routineN, handle)
      CALL dbcsr_iterator_start(iter, matrix_a)

      DO WHILE (dbcsr_iterator_blocks_left(iter))
         CALL dbcsr_iterator_next_block(iter, row, col, DATA, tr, &
                                        block_number=blk, row_size=row_size, col_size=col_size)
         blk_nze = row_size*col_size
         IF (row .GT. col) CALL dbcsr_remove_block(matrix_a, row, col, blk_nze, blk)
         IF (row .EQ. col) THEN
            DO j = 1, col_size
            DO i = j + 1, row_size
               DATA(i, j) = 0.0_dp
            END DO
            END DO
         END IF
      END DO

      CALL dbcsr_iterator_stop(iter)

      CALL dbcsr_finalize(matrix_a)
      CALL timestop(handle)
   END SUBROUTINE dbcsr_triu