view libinterp/corefcn/ls-oct-ascii.cc @ 17787:175b392e91fe

Use GNU style coding conventions for code in libinterp/ * libinterp/corefcn/Cell.h, libinterp/corefcn/__contourc__.cc, libinterp/corefcn/__dispatch__.cc, libinterp/corefcn/__lin_interpn__.cc, libinterp/corefcn/__pchip_deriv__.cc, libinterp/corefcn/__qp__.cc, libinterp/corefcn/balance.cc, libinterp/corefcn/besselj.cc, libinterp/corefcn/betainc.cc, libinterp/corefcn/bitfcns.cc, libinterp/corefcn/bsxfun.cc, libinterp/corefcn/c-file-ptr-stream.cc, libinterp/corefcn/c-file-ptr-stream.h, libinterp/corefcn/cellfun.cc, libinterp/corefcn/colloc.cc, libinterp/corefcn/comment-list.h, libinterp/corefcn/conv2.cc, libinterp/corefcn/daspk.cc, libinterp/corefcn/dasrt.cc, libinterp/corefcn/dassl.cc, libinterp/corefcn/data.cc, libinterp/corefcn/debug.cc, libinterp/corefcn/defaults.cc, libinterp/corefcn/defaults.in.h, libinterp/corefcn/defun-int.h, libinterp/corefcn/defun.cc, libinterp/corefcn/det.cc, libinterp/corefcn/dirfns.cc, libinterp/corefcn/display.cc, libinterp/corefcn/dlmread.cc, libinterp/corefcn/dot.cc, libinterp/corefcn/dynamic-ld.cc, libinterp/corefcn/dynamic-ld.h, libinterp/corefcn/eig.cc, libinterp/corefcn/ellipj.cc, libinterp/corefcn/error.cc, libinterp/corefcn/error.h, libinterp/corefcn/event-queue.h, libinterp/corefcn/fft.cc, libinterp/corefcn/fft2.cc, libinterp/corefcn/fftn.cc, libinterp/corefcn/file-io.cc, libinterp/corefcn/filter.cc, libinterp/corefcn/find.cc, libinterp/corefcn/gammainc.cc, libinterp/corefcn/gcd.cc, libinterp/corefcn/getgrent.cc, libinterp/corefcn/getpwent.cc, libinterp/corefcn/getrusage.cc, libinterp/corefcn/givens.cc, libinterp/corefcn/gl-render.cc, libinterp/corefcn/gl2ps-renderer.cc, libinterp/corefcn/gl2ps-renderer.h, libinterp/corefcn/graphics.cc, libinterp/corefcn/graphics.in.h, libinterp/corefcn/gripes.cc, libinterp/corefcn/gripes.h, libinterp/corefcn/help.cc, libinterp/corefcn/hess.cc, libinterp/corefcn/hex2num.cc, libinterp/corefcn/input.cc, libinterp/corefcn/input.h, libinterp/corefcn/inv.cc, libinterp/corefcn/jit-ir.h, libinterp/corefcn/jit-typeinfo.cc, libinterp/corefcn/jit-typeinfo.h, libinterp/corefcn/jit-util.h, libinterp/corefcn/kron.cc, libinterp/corefcn/load-path.cc, libinterp/corefcn/load-path.h, libinterp/corefcn/load-save.cc, libinterp/corefcn/load-save.h, libinterp/corefcn/lookup.cc, libinterp/corefcn/ls-ascii-helper.cc, libinterp/corefcn/ls-hdf5.cc, libinterp/corefcn/ls-hdf5.h, libinterp/corefcn/ls-mat-ascii.cc, libinterp/corefcn/ls-mat-ascii.h, libinterp/corefcn/ls-mat4.cc, libinterp/corefcn/ls-mat5.cc, libinterp/corefcn/ls-mat5.h, libinterp/corefcn/ls-oct-ascii.cc, libinterp/corefcn/lsode.cc, libinterp/corefcn/lu.cc, libinterp/corefcn/luinc.cc, libinterp/corefcn/mappers.cc, libinterp/corefcn/matrix_type.cc, libinterp/corefcn/max.cc, libinterp/corefcn/md5sum.cc, libinterp/corefcn/mex.cc, libinterp/corefcn/mexproto.h, libinterp/corefcn/mgorth.cc, libinterp/corefcn/mxarray.in.h, libinterp/corefcn/nproc.cc, libinterp/corefcn/oct-hist.cc, libinterp/corefcn/oct-lvalue.h, libinterp/corefcn/oct-map.cc, libinterp/corefcn/oct-map.h, libinterp/corefcn/oct-obj.h, libinterp/corefcn/oct-prcstrm.h, libinterp/corefcn/oct-stdstrm.h, libinterp/corefcn/oct-stream.cc, libinterp/corefcn/oct-stream.h, libinterp/corefcn/octave-link.cc, libinterp/corefcn/octave-link.h, libinterp/corefcn/pager.cc, libinterp/corefcn/pinv.cc, libinterp/corefcn/pr-output.cc, libinterp/corefcn/procstream.h, libinterp/corefcn/profiler.cc, libinterp/corefcn/pt-jit.cc, libinterp/corefcn/pt-jit.h, libinterp/corefcn/quad.cc, libinterp/corefcn/quadcc.cc, libinterp/corefcn/qz.cc, libinterp/corefcn/rand.cc, libinterp/corefcn/rcond.cc, libinterp/corefcn/regexp.cc, libinterp/corefcn/schur.cc, libinterp/corefcn/sighandlers.cc, libinterp/corefcn/sighandlers.h, libinterp/corefcn/sparse-xdiv.cc, libinterp/corefcn/sparse-xdiv.h, libinterp/corefcn/sparse-xpow.cc, libinterp/corefcn/sparse.cc, libinterp/corefcn/spparms.cc, libinterp/corefcn/sqrtm.cc, libinterp/corefcn/str2double.cc, libinterp/corefcn/strfind.cc, libinterp/corefcn/strfns.cc, libinterp/corefcn/sub2ind.cc, libinterp/corefcn/svd.cc, libinterp/corefcn/syl.cc, libinterp/corefcn/symtab.cc, libinterp/corefcn/symtab.h, libinterp/corefcn/syscalls.cc, libinterp/corefcn/sysdep.cc, libinterp/corefcn/sysdep.h, libinterp/corefcn/time.cc, libinterp/corefcn/toplev.cc, libinterp/corefcn/toplev.h, libinterp/corefcn/tril.cc, libinterp/corefcn/txt-eng-ft.cc, libinterp/corefcn/txt-eng-ft.h, libinterp/corefcn/txt-eng.h, libinterp/corefcn/typecast.cc, libinterp/corefcn/urlwrite.cc, libinterp/corefcn/utils.cc, libinterp/corefcn/variables.cc, libinterp/corefcn/variables.h, libinterp/corefcn/xdiv.cc, libinterp/corefcn/xdiv.h, libinterp/corefcn/xnorm.h, libinterp/corefcn/xpow.cc, libinterp/corefcn/xpow.h, libinterp/corefcn/zfstream.cc, libinterp/corefcn/zfstream.h, libinterp/dldfcn/__delaunayn__.cc, libinterp/dldfcn/__dsearchn__.cc, libinterp/dldfcn/__eigs__.cc, libinterp/dldfcn/__fltk_uigetfile__.cc, libinterp/dldfcn/__glpk__.cc, libinterp/dldfcn/__init_fltk__.cc, libinterp/dldfcn/__init_gnuplot__.cc, libinterp/dldfcn/__magick_read__.cc, libinterp/dldfcn/__voronoi__.cc, libinterp/dldfcn/amd.cc, libinterp/dldfcn/ccolamd.cc, libinterp/dldfcn/chol.cc, libinterp/dldfcn/colamd.cc, libinterp/dldfcn/convhulln.cc, libinterp/dldfcn/dmperm.cc, libinterp/dldfcn/fftw.cc, libinterp/dldfcn/qr.cc, libinterp/dldfcn/symbfact.cc, libinterp/dldfcn/symrcm.cc, libinterp/dldfcn/tsearch.cc, libinterp/octave-value/ov-base-diag.cc, libinterp/octave-value/ov-base-diag.h, libinterp/octave-value/ov-base-int.cc, libinterp/octave-value/ov-base-int.h, libinterp/octave-value/ov-base-mat.h, libinterp/octave-value/ov-base-scalar.cc, libinterp/octave-value/ov-base-scalar.h, libinterp/octave-value/ov-base-sparse.cc, libinterp/octave-value/ov-base-sparse.h, libinterp/octave-value/ov-base.cc, libinterp/octave-value/ov-base.h, libinterp/octave-value/ov-bool-mat.cc, libinterp/octave-value/ov-bool-mat.h, libinterp/octave-value/ov-bool-sparse.cc, libinterp/octave-value/ov-bool-sparse.h, libinterp/octave-value/ov-bool.cc, libinterp/octave-value/ov-bool.h, libinterp/octave-value/ov-builtin.cc, libinterp/octave-value/ov-builtin.h, libinterp/octave-value/ov-cell.cc, libinterp/octave-value/ov-cell.h, libinterp/octave-value/ov-ch-mat.cc, libinterp/octave-value/ov-ch-mat.h, libinterp/octave-value/ov-class.cc, libinterp/octave-value/ov-class.h, libinterp/octave-value/ov-colon.h, libinterp/octave-value/ov-complex.cc, libinterp/octave-value/ov-complex.h, libinterp/octave-value/ov-cx-diag.cc, libinterp/octave-value/ov-cx-diag.h, libinterp/octave-value/ov-cx-mat.cc, libinterp/octave-value/ov-cx-mat.h, libinterp/octave-value/ov-cx-sparse.cc, libinterp/octave-value/ov-cx-sparse.h, libinterp/octave-value/ov-dld-fcn.h, libinterp/octave-value/ov-fcn-handle.cc, libinterp/octave-value/ov-fcn-handle.h, libinterp/octave-value/ov-fcn-inline.cc, libinterp/octave-value/ov-fcn-inline.h, libinterp/octave-value/ov-fcn.h, libinterp/octave-value/ov-float.cc, libinterp/octave-value/ov-float.h, libinterp/octave-value/ov-flt-complex.cc, libinterp/octave-value/ov-flt-complex.h, libinterp/octave-value/ov-flt-cx-diag.cc, libinterp/octave-value/ov-flt-cx-diag.h, libinterp/octave-value/ov-flt-cx-mat.cc, libinterp/octave-value/ov-flt-cx-mat.h, libinterp/octave-value/ov-flt-re-diag.cc, libinterp/octave-value/ov-flt-re-diag.h, libinterp/octave-value/ov-flt-re-mat.cc, libinterp/octave-value/ov-flt-re-mat.h, libinterp/octave-value/ov-int16.cc, libinterp/octave-value/ov-int32.cc, libinterp/octave-value/ov-int64.cc, libinterp/octave-value/ov-int8.cc, libinterp/octave-value/ov-intx.h, libinterp/octave-value/ov-java.cc, libinterp/octave-value/ov-lazy-idx.h, libinterp/octave-value/ov-mex-fcn.cc, libinterp/octave-value/ov-mex-fcn.h, libinterp/octave-value/ov-null-mat.cc, libinterp/octave-value/ov-null-mat.h, libinterp/octave-value/ov-oncleanup.cc, libinterp/octave-value/ov-perm.cc, libinterp/octave-value/ov-perm.h, libinterp/octave-value/ov-range.cc, libinterp/octave-value/ov-range.h, libinterp/octave-value/ov-re-diag.cc, libinterp/octave-value/ov-re-diag.h, libinterp/octave-value/ov-re-mat.cc, libinterp/octave-value/ov-re-mat.h, libinterp/octave-value/ov-re-sparse.cc, libinterp/octave-value/ov-re-sparse.h, libinterp/octave-value/ov-scalar.cc, libinterp/octave-value/ov-scalar.h, libinterp/octave-value/ov-str-mat.cc, libinterp/octave-value/ov-str-mat.h, libinterp/octave-value/ov-struct.cc, libinterp/octave-value/ov-struct.h, libinterp/octave-value/ov-type-conv.h, libinterp/octave-value/ov-typeinfo.cc, libinterp/octave-value/ov-typeinfo.h, libinterp/octave-value/ov-uint16.cc, libinterp/octave-value/ov-uint32.cc, libinterp/octave-value/ov-uint64.cc, libinterp/octave-value/ov-uint8.cc, libinterp/octave-value/ov-usr-fcn.cc, libinterp/octave-value/ov-usr-fcn.h, libinterp/octave-value/ov.cc, libinterp/octave-value/ov.h, libinterp/octave.cc, libinterp/operators/op-b-bm.cc, libinterp/operators/op-b-sbm.cc, libinterp/operators/op-bm-b.cc, libinterp/operators/op-bm-bm.cc, libinterp/operators/op-cdm-cdm.cc, libinterp/operators/op-chm.cc, libinterp/operators/op-class.cc, libinterp/operators/op-cm-cm.cc, libinterp/operators/op-cm-cs.cc, libinterp/operators/op-cm-s.cc, libinterp/operators/op-cm-scm.cc, libinterp/operators/op-cm-sm.cc, libinterp/operators/op-cs-cm.cc, libinterp/operators/op-cs-cs.cc, libinterp/operators/op-cs-scm.cc, libinterp/operators/op-cs-sm.cc, libinterp/operators/op-dm-dm.cc, libinterp/operators/op-dm-scm.cc, libinterp/operators/op-double-conv.cc, libinterp/operators/op-fcdm-fcdm.cc, libinterp/operators/op-fcm-fcm.cc, libinterp/operators/op-fcm-fcs.cc, libinterp/operators/op-fcm-fm.cc, libinterp/operators/op-fcm-fs.cc, libinterp/operators/op-fcs-fcm.cc, libinterp/operators/op-fcs-fcs.cc, libinterp/operators/op-fcs-fm.cc, libinterp/operators/op-fcs-fs.cc, libinterp/operators/op-fdm-fdm.cc, libinterp/operators/op-float-conv.cc, libinterp/operators/op-fm-fcm.cc, libinterp/operators/op-fm-fcs.cc, libinterp/operators/op-fm-fm.cc, libinterp/operators/op-fm-fs.cc, libinterp/operators/op-fs-fcm.cc, libinterp/operators/op-fs-fcs.cc, libinterp/operators/op-fs-fm.cc, libinterp/operators/op-fs-fs.cc, libinterp/operators/op-m-cm.cc, libinterp/operators/op-m-cs.cc, libinterp/operators/op-m-m.cc, libinterp/operators/op-m-s.cc, libinterp/operators/op-m-scm.cc, libinterp/operators/op-m-sm.cc, libinterp/operators/op-pm-scm.cc, libinterp/operators/op-range.cc, libinterp/operators/op-s-cm.cc, libinterp/operators/op-s-cs.cc, libinterp/operators/op-s-scm.cc, libinterp/operators/op-sbm-b.cc, libinterp/operators/op-sbm-bm.cc, libinterp/operators/op-sbm-sbm.cc, libinterp/operators/op-scm-cm.cc, libinterp/operators/op-scm-cs.cc, libinterp/operators/op-scm-m.cc, libinterp/operators/op-scm-s.cc, libinterp/operators/op-scm-scm.cc, libinterp/operators/op-scm-sm.cc, libinterp/operators/op-sm-cm.cc, libinterp/operators/op-sm-m.cc, libinterp/operators/op-sm-s.cc, libinterp/operators/op-sm-scm.cc, libinterp/operators/op-sm-sm.cc, libinterp/operators/op-str-m.cc, libinterp/operators/op-str-s.cc, libinterp/operators/op-str-str.cc, libinterp/operators/ops.h, libinterp/parse-tree/lex.h, libinterp/parse-tree/parse.h, libinterp/parse-tree/pt-arg-list.cc, libinterp/parse-tree/pt-arg-list.h, libinterp/parse-tree/pt-assign.cc, libinterp/parse-tree/pt-assign.h, libinterp/parse-tree/pt-binop.cc, libinterp/parse-tree/pt-binop.h, libinterp/parse-tree/pt-bp.h, libinterp/parse-tree/pt-cbinop.cc, libinterp/parse-tree/pt-check.cc, libinterp/parse-tree/pt-colon.cc, libinterp/parse-tree/pt-colon.h, libinterp/parse-tree/pt-const.cc, libinterp/parse-tree/pt-decl.cc, libinterp/parse-tree/pt-decl.h, libinterp/parse-tree/pt-eval.cc, libinterp/parse-tree/pt-except.h, libinterp/parse-tree/pt-exp.h, libinterp/parse-tree/pt-fcn-handle.cc, libinterp/parse-tree/pt-id.cc, libinterp/parse-tree/pt-id.h, libinterp/parse-tree/pt-idx.cc, libinterp/parse-tree/pt-idx.h, libinterp/parse-tree/pt-loop.h, libinterp/parse-tree/pt-mat.cc, libinterp/parse-tree/pt-misc.cc, libinterp/parse-tree/pt-misc.h, libinterp/parse-tree/pt-pr-code.cc, libinterp/parse-tree/pt-select.h, libinterp/parse-tree/pt-stmt.h, libinterp/parse-tree/token.h, libinterp/version.cc: Use GNU style coding conventions for code in libinterp/
author Rik <rik@octave.org>
date Mon, 28 Oct 2013 19:51:46 -0700
parents d63878346099
children 4197fc428c7d
line wrap: on
line source

/*

Copyright (C) 1996-2013 John W. Eaton

This file is part of Octave.

Octave is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.

Octave is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, see
<http://www.gnu.org/licenses/>.

*/

// Author: John W. Eaton.

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <cstring>
#include <cctype>

#include <fstream>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <string>

#include "byte-swap.h"
#include "data-conv.h"
#include "file-ops.h"
#include "glob-match.h"
#include "lo-mappers.h"
#include "mach-info.h"
#include "oct-env.h"
#include "oct-time.h"
#include "quit.h"
#include "str-vec.h"

#include "Cell.h"
#include "defun.h"
#include "error.h"
#include "gripes.h"
#include "load-save.h"
#include "ls-ascii-helper.h"
#include "ls-oct-ascii.h"
#include "oct-obj.h"
#include "oct-map.h"
#include "ov-cell.h"
#include "pager.h"
#include "pt-exp.h"
#include "unwind-prot.h"
#include "utils.h"
#include "variables.h"
#include "version.h"
#include "dMatrix.h"

// The number of decimal digits to use when writing ascii data.
static int Vsave_precision = 16;

// Functions for reading ascii data.

// Extract a KEYWORD and its value from stream IS, returning the
// associated value in a new string.
//
// Input should look something like:
//
//  [%#][ \t]*keyword[ \t]*:[ \t]*string-value[ \t]*\n

std::string
extract_keyword (std::istream& is, const char *keyword, const bool next_only)
{
  std::string retval;

  int ch = is.peek ();
  if (next_only && ch != '%' && ch != '#')
    return retval;

  char c;
  while (is.get (c))
    {
      if (c == '%' || c == '#')
        {
          std::ostringstream buf;

          while (is.get (c) && (c == ' ' || c == '\t' || c == '%' || c == '#'))
            ; // Skip whitespace and comment characters.

          if (isalpha (c))
            buf << c;

          while (is.get (c) && isalpha (c))
            buf << c;

          std::string tmp = buf.str ();
          bool match = (tmp.compare (0, strlen (keyword), keyword) == 0);

          if (match)
            {
              std::ostringstream value;
              while (is.get (c) && (c == ' ' || c == '\t' || c == ':'))
                ; // Skip whitespace and the colon.

              is.putback (c);
              retval = read_until_newline (is, false);
              break;
            }
          else if (next_only)
            break;
          else
            skip_until_newline (is, false);
        }
    }

  int len = retval.length ();

  if (len > 0)
    {
      while (len)
        {
          c = retval[len-1];

          if (c == ' ' || c == '\t')
            len--;
          else
            {
              retval.resize (len);
              break;
            }
        }
    }

  return retval;
}

// Extract one value (scalar, matrix, string, etc.) from stream IS and
// place it in TC, returning the name of the variable.  If the value
// is tagged as global in the file, return TRUE in GLOBAL.
//
// Each type supplies its own function to load the data, and so this
// function is extensible.
//
// FILENAME is used for error messages.
//
// The data is expected to be in the following format:
//
// The input file must have a header followed by some data.
//
// All lines in the header must begin with a '#' character.
//
// The header must contain a list of keyword and value pairs with the
// keyword and value separated by a colon.
//
// Keywords must appear in the following order:
//
// # name: <name>
// # type: <type>
// # <info>
//
// Where, for the built in types are:
//
//  <name> : a valid identifier
//
//  <type> : <typename>
//         | global <typename>
//
//  <typename> : scalar
//             | complex scalar
//             | matrix
//             | complex matrix
//             | bool
//             | bool matrix
//             | string
//             | range
//
//  <info> : <matrix info>
//         | <string info>
//
//  <matrix info> : # rows: <integer>
//                : # columns: <integer>
//
//  <string info> : # elements: <integer>
//                : # length: <integer> (once before each string)
//
//  For backward compatibility the type "string array" is treated as a
// "string" type. Also "string" can have a single element with no elements
// line such that
//
//  <string info> : # length: <integer>
//
// Formatted ASCII data follows the header.
//
// Example:
//
//  # name: foo
//  # type: matrix
//  # rows: 2
//  # columns: 2
//    2  4
//    1  3
//
// Example:
//
//  # name: foo
//  # type: string
//  # elements: 5
//  # length: 4
//  this
//  # length: 2
//  is
//  # length: 1
//  a
//  # length: 6
//  string
//  # length: 5
//  array
//
// FIXME: this format is fairly rigid, and doesn't allow for
// arbitrary comments.  Someone should fix that. It does allow arbitrary
// types however.

// Ugh.  The signature of the compare method is not standard in older
// versions of the GNU libstdc++.  Do this instead:

#define SUBSTRING_COMPARE_EQ(s, pos, n, t) (s.substr (pos, n) == t)

std::string
read_ascii_data (std::istream& is, const std::string& filename, bool& global,
                 octave_value& tc, octave_idx_type count)
{
  // Read name for this entry or break on EOF.

  std::string name = extract_keyword (is, "name");

  if (name.empty ())
    {
      if (count == 0)
        error ("load: empty name keyword or no data found in file '%s'",
               filename.c_str ());

      return std::string ();
    }

  if (! (name == ".nargin." || name == ".nargout."
         || name == CELL_ELT_TAG || valid_identifier (name)))
    {
      error ("load: bogus identifier '%s' found in file '%s'",
             name.c_str (), filename.c_str ());
      return std::string ();
    }

  // Look for type keyword.

  std::string tag = extract_keyword (is, "type");

  if (! tag.empty ())
    {
      std::string typ;
      size_t pos = tag.rfind (' ');

      if (pos != std::string::npos)
        {
          global = SUBSTRING_COMPARE_EQ (tag, 0, 6, "global");

          typ = global ? tag.substr (7) : tag;
        }
      else
        typ = tag;

      // Special case for backward compatiablity. A small bit of cruft
      if (SUBSTRING_COMPARE_EQ (typ, 0, 12, "string array"))
        tc = charMatrix ();
      else
        tc = octave_value_typeinfo::lookup_type (typ);

      if (! tc.load_ascii (is))
        error ("load: trouble reading ascii file '%s'", filename.c_str ());
    }
  else
    error ("load: failed to extract keyword specifying value type");

  if (error_state)
    {
      error ("load: reading file %s", filename.c_str ());
      return std::string ();
    }

  return name;
}

// Save the data from TC along with the corresponding NAME, and global
// flag MARK_AS_GLOBAL on stream OS in the plain text format described
// above for load_ascii_data.  If NAME is empty, the name: line is not
// generated.  PRECISION specifies the number of decimal digits to print.
//
// Assumes ranges and strings cannot contain Inf or NaN values.
//
// Returns 1 for success and 0 for failure.

// FIXME: should probably write the help string here too.

bool
save_ascii_data (std::ostream& os, const octave_value& val_arg,
                 const std::string& name, bool mark_as_global,
                 int precision)
{
  bool success = true;

  if (! name.empty ())
    os << "# name: " << name << "\n";

  octave_value val = val_arg;

  if (mark_as_global)
    os << "# type: global " << val.type_name () << "\n";
  else
    os << "# type: " << val.type_name () << "\n";

  if (! precision)
    precision = Vsave_precision;

  long old_precision = os.precision ();
  os.precision (precision);

  success = val.save_ascii (os);

  // Insert an extra pair of newline characters after the data so that
  // multiple data elements may be handled separately by gnuplot (see
  // the description of the index qualifier for the plot command in the
  // gnuplot documentation).
  os << "\n\n";

  os.precision (old_precision);

  return (os && success);
}

bool
save_ascii_data_for_plotting (std::ostream& os, const octave_value& t,
                              const std::string& name)
{
  return save_ascii_data (os, t, name, false, 6);
}

// Maybe this should be a static function in tree-plot.cc?

// If TC is matrix, save it on stream OS in a format useful for
// making a 3-dimensional plot with gnuplot.  If PARAMETRIC is
// TRUE, assume a parametric 3-dimensional plot will be generated.

bool
save_three_d (std::ostream& os, const octave_value& tc, bool parametric)
{
  bool fail = false;

  octave_idx_type nr = tc.rows ();
  octave_idx_type nc = tc.columns ();

  if (tc.is_real_matrix ())
    {
      os << "# 3-D data...\n"
         << "# type: matrix\n"
         << "# total rows: " << nr << "\n"
         << "# total columns: " << nc << "\n";

      long old_precision = os.precision ();
      os.precision (6);

      if (parametric)
        {
          octave_idx_type extras = nc % 3;
          if (extras)
            warning ("ignoring last %d columns", extras);

          Matrix tmp = tc.matrix_value ();
          nr = tmp.rows ();

          for (octave_idx_type i = 0; i < nc-extras; i += 3)
            {
              os << tmp.extract (0, i, nr-1, i+2);
              if (i+3 < nc-extras)
                os << "\n";
            }
        }
      else
        {
          Matrix tmp = tc.matrix_value ();
          nr = tmp.rows ();

          for (octave_idx_type i = 0; i < nc; i++)
            {
              os << tmp.extract (0, i, nr-1, i);
              if (i+1 < nc)
                os << "\n";
            }
        }

      os.precision (old_precision);
    }
  else
    {
      ::error ("for now, I can only save real matrices in 3-D format");
      fail = true;
    }

  return (os && ! fail);
}

DEFUN (save_precision, args, nargout,
       "-*- texinfo -*-\n\
@deftypefn  {Built-in Function} {@var{val} =} save_precision ()\n\
@deftypefnx {Built-in Function} {@var{old_val} =} save_precision (@var{new_val})\n\
@deftypefnx {Built-in Function} {} save_precision (@var{new_val}, \"local\")\n\
Query or set the internal variable that specifies the number of\n\
digits to keep when saving data in text format.\n\
\n\
When called from inside a function with the @qcode{\"local\"} option, the\n\
variable is changed locally for the function and any subroutines it calls.\n\
The original variable value is restored when exiting the function.\n\
@end deftypefn")
{
  return SET_INTERNAL_VARIABLE_WITH_LIMITS (save_precision, -1,
                                            std::numeric_limits<int>::max ());
}