text: /* ========================================================================== */
  /* === UMFPACK_col_to_triplet =============================================== */
  /* ========================================================================== */
  
  /* -------------------------------------------------------------------------- */
  /* UMFPACK Version 4.4, Copyright (c) 2005 by Timothy A. Davis.  CISE Dept,   */
  /* Univ. of Florida.  All Rights Reserved.  See ../Doc/License for License.   */
  /* web: http://www.cise.ufl.edu/research/sparse/umfpack                       */
  /* -------------------------------------------------------------------------- */
  
  /*
      User callable.  Converts a column-oriented input matrix to triplet form by
      constructing the column indices Tj from the column pointers Ap.  The matrix
      may be singular.  See umfpack_col_to_triplet.h for details.
  
  */
  
  #include "umf_internal.h"
  
  GLOBAL Int UMFPACK_col_to_triplet
  (
      Int n_col,
      const Int Ap [ ],
      Int Tj [ ]
  )
  {
  
      /* ---------------------------------------------------------------------- */
      /* local variables */
      /* ---------------------------------------------------------------------- */
  
      Int nz, j, p, p1, p2, length ;
  
      /* ---------------------------------------------------------------------- */
      /* construct the column indices */
      /* ---------------------------------------------------------------------- */
  
      if (!Ap || !Tj)
      {
  	return (UMFPACK_ERROR_argument_missing) ;
      }
      if (n_col <= 0)
      {
  	return (UMFPACK_ERROR_n_nonpositive) ;
      }
      if (Ap [0] != 0)
      {
  	return (UMFPACK_ERROR_invalid_matrix) ;
      }
      nz = Ap [n_col] ;
      if (nz < 0)
      {
  	return (UMFPACK_ERROR_invalid_matrix) ;
      }
  
      for (j = 0 ; j < n_col ; j++)
      {
  	p1 = Ap [j] ;
  	p2 = Ap [j+1] ;
  	length = p2 - p1 ;
  	if (length < 0 || p2 > nz)
  	{
  	    return (UMFPACK_ERROR_invalid_matrix) ;
  	}
  	for (p = p1 ; p < p2 ; p++)
  	{
  	    Tj [p] = j ;
  	}
      }
  
      return (UMFPACK_OK) ;
  }
  