subroutine ccs_print ( m, n, ncc, icc, ccc, acc, title )

!*****************************************************************************80
!
!! ccs_print() prints a sparse matrix in CCS format.
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    23 July 2014
!
!  Author:
!
!    John Burkardt
!
!  Parameters:
!
!    Input, integer M, the number of rows in the matrix.
!
!    Input, integer N, the number of columns in the matrix.
!
!    Input, integer NCC, the number of CCS elements.
!
!    Input, integer ICC(NCC), the CCS rows.
!
!    Input, integer CCC(N+1), the compressed CCS columns.
!
!    Input, real ( kind = rk ) ACC(NCC), the CCS values.
!
!    Input, character ( len = * ) TITLE, a title.
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer n
  integer ncc

  real ( kind = rk ) acc(ncc)
  integer ccc(n+1)
  integer i
  integer icc(ncc)
  integer j
  integer k
  integer m
  character ( len = * ) title

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) trim ( title )
  write ( *, '(i4,a,i4,a)' ) m, ' rows by ', n, ' columns'
  write ( *, '(a)' ) '     #     I     J         A'
  write ( *, '(a)' ) '  ----  ----  ----  ----------------'
  write ( *, '(a)' ) ' '

  if ( ccc(1) == 0 ) then

    j = 0
    do k = 1, ncc
      i = icc(k)
      do while ( ccc(j+2) <= k - 1 )
        j = j + 1
      end do
      write ( *, '(2x,i4,2x,i4,2x,i4,2x,g16.8)' ) k - 1, i, j, acc(k)
    end do

  else

    j = 1
    do k = 1, ncc
      i = icc(k)
      do while ( ccc(j+1) <= k )
        j = j + 1
      end do
      write ( *, '(2x,i4,2x,i4,2x,i4,2x,g16.8)' ) k, i, j, acc(k)
    end do

  end if

  return
end
subroutine ccs_to_st ( m, n, ncc, icc, ccc, acc, nst, ist, jst, ast )

!*****************************************************************************80
!
!! ccs_to_st() converts sparse matrix information from CCS to ST format.
!
!  Discussion:
!
!    Only JST actually needs to be computed.  The other three output 
!    quantities are simply copies.  
!    
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    23 July 2014
!
!  Author:
!
!    John Burkardt
!
!  Parameters:
!
!    Input, integer M, the number of rows.
!
!    Input, integer N, the number of columns.
!
!    Input, integer NCC, the number of CCS elements.
!
!    Input, integer ICC(NCC), the CCS rows.
!
!    Input, integer CCC(N+1), the CCS compressed columns.
!
!    Input, real ( kind = rk ) ACC(NCC), the CCS values.
!
!    Output, integer NST, the number of ST elements.
!
!    Output, integer IST(NST), JST(NST), the ST rows and columns.
!
!    Output, real ( kind = rk ) AST(NST), the ST values.
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer n
  integer ncc

  real ( kind = rk ) ast(ncc)
  real ( kind = rk ) acc(ncc)
  integer ccc(n+1)
  integer icc(ncc)
  integer ist(ncc)
  integer j
  integer jhi
  integer jlo
  integer jst(ncc)
  integer k
  integer khi
  integer klo
  integer m
  integer nst

  call i4_fake_use ( m )

  nst = 0

  if ( ccc(1) == 0 ) then

    jlo = 0
    jhi = n - 1
  
    do j = jlo, jhi

      klo = ccc(j+1)
      khi = ccc(j+2) - 1

      do k = klo, khi

        nst = nst + 1
        ist(nst) = icc(k+1)
        jst(nst) = j
        ast(nst) = acc(k+1)

      end do

    end do

  else

    jlo = 1
    jhi = n
  
    do j = jlo, jhi

      klo = ccc(j)
      khi = ccc(j+1) - 1

      do k = klo, khi

        nst = nst + 1
        ist(nst) = icc(k)
        jst(nst) = j
        ast(nst) = acc(k)

      end do

    end do

  end if

  return
end
subroutine i4_fake_use ( n )

!*****************************************************************************80
!
!! i4_fake_use() pretends to use a variable.
!
!  Discussion:
!
!    Some compilers will issue a warning if a variable is unused.
!    Sometimes there's a good reason to include a variable in a program,
!    but not to use it.  Calling this function with that variable as
!    the argument will shut the compiler up.
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    21 April 2020
!
!  Author:
!
!    John Burkardt
!
!  Input:
!
!    integer N, the variable to be "used".
!
  implicit none

  integer n

  if ( n /= n ) then
    write ( *, '(a)' ) '  i4_fake_use(): variable is NAN.'
  end if

  return
end
subroutine st_print ( m, n, nst, ist, jst, ast, title )

!*****************************************************************************80
!
!! st_print() prints a sparse matrix in ST format.
!
!  Licensing:
!
!    This code is distributed under the MIT license.
!
!  Modified:
!
!    21 July 2014
!
!  Author:
!
!    John Burkardt
!
!  Parameters:
!
!    Input, integer M, the number of rows.
!
!    Input, integer N, the number of columns.
!
!    Input, integer NST, the number of ST elements.
!
!    Input, integer IST(NST), JST(NST), the ST rows and columns.
!
!    Input, real ( kind = rk ) AST(NST), the ST values.
!
!    Input, character ( len = * ) TITLE, a title.
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  integer nst

  real ( kind = rk ) ast(nst)
  integer ist(nst)
  integer jst(nst)
  integer k
  integer m
  integer n
  character ( len = * ) title

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) trim ( title )
  write ( *, '(i4,a,i4,a)' ) m, ' rows by ', n, ' columns'
  write ( *, '(a)' ) '     #     I     J       A'
  write ( *, '(a)' ) '  ----  ----  ----  --------------'
  write ( *, '(a)' ) ' '

  do k = 1, nst
    write ( *, '(2x,i4,2x,i4,2x,i4,2x,g16.8)' ) k, ist(k), jst(k), ast(k)
  end do

  return
end