#! /usr/bin/env python
#
def r8st_sort_a ( m, n, nst, ist, jst, ast ):

#*****************************************************************************80
#
## R8ST_SORT_A sorts the entries of an R8ST matrix by column.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    27 September 2018
#
#  Author:
#
#    John Burkardt
#
#  Parameters:
#
#    Input, integer M, the number of rows.
#
#    Input, integer N, the number of columns.
#
#    Input, integer NST, the number of nonzeros.
#
#    Input/output, integer IST(NST), JST(NST), the row and column indices.
#
#    Input/output, real AST(NST), the nonzero matrix values.
#
  from sort_heap_external import sort_heap_external
#
#  Initialize.
#
  i = 0
  indx = 0
  isgn = 0
  j = 0

  i1 = 0
  j1 = 0
  k0 = 0
  k1 = 0
  n1 = 0
#
#  Call the external heap sorter.
#
  while ( True ):

    indx, i, j, i1, j1, k0, k1, n1 = sort_heap_external ( nst, indx, isgn, \
      i1, j1, k0, k1, n1 )
#
#  Interchange the I and J objects.
#
    if ( 0 < indx ):

      rij    = ist[i]
      ist[i] = ist[j]
      ist[j] = rij

      cij    = jst[i]
      jst[i] = jst[j]
      jst[j] = cij

      aij    = ast[i]
      ast[i] = ast[j]
      ast[j] = aij
#
#  Compare the I and J objects.
#
    elif ( indx < 0 ):

      if ( jst[i] == jst[j] ):

        if ( ist[i] < ist[j] ):
          isgn = - 1
        elif ( ist[i] == ist[j] ):
          isgn = 0
        elif ( ist[j] < ist[i] ):
          isgn = + 1

      elif ( jst[i] < jst[j] ):

        isgn = - 1

      elif ( jst[j] < jst[i] ):

        isgn = + 1

    elif ( indx == 0 ):

      break

  return ist, jst, ast

def r8st_sort_a_test ( ):

#*****************************************************************************80
#
## R8ST_SORT_A_TEST tests R8ST_SORT_A.
#
#  Discussion:
#
#    The matrix is:
#
#      11  12   0   0  15
#      21  22   0   0   0
#       0   0  33   0  35
#       0   0   0  44   0
#      51   0  53   0  55
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    27 September 2018
#
#  Author:
#
#    John Burkardt
#
  import numpy as np
  import platform
  from r8st_header_print import r8st_header_print
  from r8st_print import r8st_print

  m = 5
  n = 5
  nst = 11
  ast = np.array ( [ 51.0, 12.0, 11.0, 33.0, 15.0, 53.0, 55.0, 22.0, 35.0, 44.0, 21.0 ] )
  ist = np.array ( [ 5, 1, 1, 3, 1, 5, 5, 2, 3, 4, 2 ] )
  jst = np.array ( [ 1, 2, 1, 3, 5, 3, 5, 2, 5, 4, 1 ] )

  print ( '' )
  print ( 'R8ST_SORT_A_TEST' )
  print ( '  Python version: %s' % ( platform.python_version ( ) ) )
  print ( '  R8ST_SORT_A sorts an R8ST matrix by columns.' )

  i_min = min ( ist )
  i_max = max ( ist )
  j_min = min ( jst )
  j_max = max ( jst )

  r8st_header_print ( i_min, i_max, j_min, j_max, m, n, nst )

  r8st_print ( m, n, nst, ist, jst, ast, '  Matrix data before sorting:' )

  ist, jst, ast = r8st_sort_a ( m, n, nst, ist, jst, ast )

  r8st_print ( m, n, nst, ist, jst, ast, '  Matrix data after sorting:' )
#
#  Terminate.
#
  print ( '' )
  print ( 'R8ST_SORT_A_TEST:' )
  print ( '  Normal end of execution.' )
  return

if ( __name__ == '__main__' ):
  from timestamp import timestamp
  timestamp ( )
  r8st_sort_a_test ( )
  timestamp ( )