--- a/doc/ChangeLog	Tue Mar 25 19:47:21 2008 -0400
+++ b/doc/ChangeLog	Tue Mar 25 20:22:46 2008 -0400
@@ -1,3 +1,7 @@
+2008-03-25  David Bateman  <dbateman@free.fr>
+
+	* interpreter/strings.txi: Document hex2num, num2hex.
+	
 2008-03-21  David Bateman  <dbateman@free.fr>
 
 	* interpreter/sparse.txi: Document amd function.

--- a/doc/interpreter/strings.txi	Tue Mar 25 19:47:21 2008 -0400
+++ b/doc/interpreter/strings.txi	Tue Mar 25 20:22:46 2008 -0400
@@ -297,6 +297,10 @@
 
 @DOCSTRING(base2dec)
 
+@DOCSTRING(num2hex)
+
+@DOCSTRING(hex2num)
+
 @DOCSTRING(str2double)
 
 @DOCSTRING(strjust)

--- a/src/ChangeLog	Tue Mar 25 19:47:21 2008 -0400
+++ b/src/ChangeLog	Tue Mar 25 20:22:46 2008 -0400
@@ -1,3 +1,8 @@
+2008-03-25  David Bateman  <dbateman@free.fr>
+
+	* DLD-FUNCTIONS/hex2num.cc: New function
+	* Makefile.in (DLD_XSRC): Add hex2num.cc.
+
 2008-03-25  Jaroslav Hajek  <highegg@gmail.com>
 
 	* mappers.cc (Fexpm1, Flog1p): New functions.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/DLD-FUNCTIONS/hex2num.cc	Tue Mar 25 20:22:46 2008 -0400
@@ -0,0 +1,183 @@
+/*
+
+Copyright (C) 2008 David Bateman
+
+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/>.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <algorithm>
+
+#include "defun-dld.h"
+#include "error.h"
+#include "gripes.h"
+#include "oct-obj.h"
+#include "utils.h"
+
+DEFUN_DLD (hex2num, args, ,
+  "-*- texinfo -*-\n\
+@deftypefn {Loadable Function} {@var{n} =} hex2num (@var{s})\n\
+Typecast the 16 character hexadecimal character matrix to an IEEE 754\n\
+double precision number. If fewer than 16 characters are given the\n\
+strings are right padded with '0' characters.\n\
+\n\
+Given a string matrix, @code{hex2num} treats each row as a separate\n\
+number.\n\
+\n\
+@example\n\
+hex2num ([\"4005bf0a8b145769\";\"4024000000000000\"])\n\
+@result{} [2.7183; 10.000]\n\
+@end example\n\
+@seealso{num2hex, hex2dec, dec2hex}\n\
+@end deftypefn")
+{
+  int nargin = args.length ();
+  octave_value retval;
+
+  if (nargin != 1)
+    print_usage ();
+  else
+    {
+      const charMatrix cmat = args(0).char_matrix_value ();
+
+      if (cmat.columns () > 16)
+	error ("hex2num: expecting no more than a 16 character string");
+      else if (! error_state)
+	{
+	  octave_idx_type nr = cmat.rows ();
+	  octave_idx_type nc = cmat.columns ();
+	  ColumnVector m (nr);
+
+	  for (octave_idx_type i = 0; i < nr; i++)
+	    {
+	      uint64_t num = 0;
+	      for (octave_idx_type j = 0; j < nc; j++)
+		{
+		  unsigned char ch = cmat.elem (i, j);
+
+		  if (isxdigit (ch))
+		    {
+		      num <<= 4;
+		      if (ch >= 'a')
+			num += static_cast<uint64_t> (ch - 'a' + 10);
+		      else if (ch >= 'A')
+			num += static_cast<uint64_t> (ch - 'A' + 10);
+		      else
+			num += static_cast<uint64_t> (ch - '0');
+		    }
+		  else
+		    {
+		      error ("hex2num: illegal character found in string");
+		      break;
+		    }
+		}
+
+	      if (error_state)
+		break;
+	      else
+		{
+		  if (nc < 16)
+		    num <<= (16 - nc) * 4;
+
+		  m (i) = *reinterpret_cast<double *>(&num);
+
+		}
+	    }
+
+	  if (! error_state)
+	    retval =  m;
+	}
+    }
+
+  return retval;
+}
+
+/*
+
+%!assert (hex2num(['c00';'bff';'000';'3ff';'400']),[-2:2]')
+
+ */
+
+
+
+DEFUN_DLD (num2hex, args, ,
+  "-*- texinfo -*-\n\
+@deftypefn {Loadable Function} {@var{s} =} num2hex (@var{n})\n\
+Typecast a double precision number or vector to a 16 character hexadecimal\n\
+string of the IEEE 754 representation of the number. For example\n\
+\n\
+@example\n\
+num2hex ([-1, 1, e, Inf, NaN, NA]);\n\
+@result{} \"bff0000000000000\n\
+    3ff0000000000000\n\
+    4005bf0a8b145769\n\
+    7ff0000000000000\n\
+    fff8000000000000\n\
+    7ff00000000007a2\"\n\
+@end example\n\
+@seealso{hex2num, hex2dec, dec2hex}\n\
+@end deftypefn")
+{
+  int nargin = args.length ();
+  octave_value retval;
+
+  if (nargin != 1)
+    print_usage ();
+  else
+    {
+      const ColumnVector v (args(0).vector_value ());
+
+      if (! error_state)
+	{
+	  octave_idx_type nr = v.length ();
+	  charMatrix m (nr, 16);
+	  const double *pv = v.fortran_vec ();
+
+	  for (octave_idx_type i = 0; i < nr; i++)
+	    {
+	      const uint64_t num = *reinterpret_cast<const uint64_t *> (pv++);
+	      for (octave_idx_type j = 0; j < 16; j++)
+		{
+		  unsigned char ch = 
+		    static_cast<char> (num >> ((15 - j) * 4) & 0xF);
+		  if (ch >= 10)
+		    ch += 'a' - 10;
+		  else
+		    ch += '0';
+
+		  m.elem (i, j) = ch;
+		}
+	    }
+	  
+	  retval = octave_value (m, true);
+	}
+    }
+
+  return retval;
+}
+
+/*
+
+%!assert (num2hex (-2:2),['c000000000000000';'bff0000000000000';'0000000000000000';'3ff0000000000000';'4000000000000000'])
+
+ */
+
+

--- a/src/Makefile.in	Tue Mar 25 19:47:21 2008 -0400
+++ b/src/Makefile.in	Tue Mar 25 20:22:46 2008 -0400
@@ -67,7 +67,7 @@
 	dasrt.cc dassl.cc det.cc dispatch.cc dlmread.cc dmperm.cc eig.cc \
 	expm.cc fft.cc fft2.cc fftn.cc fftw.cc filter.cc find.cc fsolve.cc \
 	gammainc.cc gcd.cc getgrent.cc getpwent.cc getrusage.cc \
-	givens.cc hess.cc inv.cc kron.cc lsode.cc \
+	givens.cc hess.cc hex2num.cc inv.cc kron.cc lsode.cc \
 	lu.cc luinc.cc matrix_type.cc md5sum.cc minmax.cc pinv.cc qr.cc \
 	quad.cc qz.cc rand.cc regexp.cc schur.cc sparse.cc \
 	spparms.cc sqrtm.cc svd.cc syl.cc symrcm.cc symbfact.cc \