# HG changeset patch
# User Jordi Gutiérrez Hermoso <jordigh@octave.org>
# Date 1348752585 14400
# Node ID 137de4fbeaf61d30e0ba811c6ca841aee77e2354
# Parent  87c3704b5c7ab85437e9339e899560e13e53d88d# Parent  46dd555edd337dad278192373aacbd37a6722ce8
Merge in Torsten's changes

diff --git a/build-aux/bootstrap_gnulib.conf b/build-aux/bootstrap_gnulib.conf
--- a/build-aux/bootstrap_gnulib.conf
+++ b/build-aux/bootstrap_gnulib.conf
@@ -45,7 +45,7 @@
   isatty
   link
   lstat
-  malloc
+  malloc-gnu
   mkdir
   mkfifo
   mkostemp
@@ -58,7 +58,7 @@
   progname
   readdir
   readlink
-  realloc
+  realloc-gnu
   rename
   rmdir
   round
diff --git a/doc/interpreter/arith.txi b/doc/interpreter/arith.txi
--- a/doc/interpreter/arith.txi
+++ b/doc/interpreter/arith.txi
@@ -118,6 +118,24 @@
 example, @code{sin} expects an angle in radians while @code{sind} expects an
 angle in degrees.
 
+Octave uses the C library trigonometric functions.  It is expected that these
+functions are defined by the ISO/IEC 9899 Standard.  This Standard is available
+at: @url{http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf}.
+Section F.9.1 deals with the trigonometric functions.  The behavior of most of
+the functions is relatively straightforward.  However, there are some
+exceptions to the standard behavior.  Many of the exceptions involve the
+behavior for -0.  The most complex case is atan2.  Octave exactly implements
+the behavior given in the Standard.  Including
+@tex
+$atan2(\pm0, -0)$ returns $\pm \pi$.
+@end tex
+@ifnottex
+@code{atan2(+- 0, 0)} returns @code{+- pi}.
+@end ifnottex
+
+It should be noted that @sc{matlab} uses different definitions which apparently
+do not distinguish -0.
+
 @DOCSTRING(sin)
 @DOCSTRING(cos)
 @DOCSTRING(tan)
diff --git a/libgnu/Makefile.am b/libgnu/Makefile.am
--- a/libgnu/Makefile.am
+++ b/libgnu/Makefile.am
@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --local-dir=gl --lib=libgnu --source-base=libgnu --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --no-conditional-dependencies --libtool --macro-prefix=gl base64 canonicalize chdir close closedir copysign copysignf crypto/md5 dup2 fclose fcntl fflush filemode floor floorf fnmatch fopen fseek ftell getcwd gethostname getopt-gnu gettimeofday glob isatty link lstat malloc mkdir mkfifo mkostemp mktime nanosleep nproc open opendir pathmax progname readdir readlink realloc rename rmdir round roundf select sigaction signal sigprocmask sleep stat stdint stdio strerror strftime strptime symlink sys_stat sys_time sys_times time times tmpfile trunc truncf unistd unlink vasprintf
+# Reproduce by: gnulib-tool --import --dir=. --local-dir=gl --lib=libgnu --source-base=libgnu --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --no-conditional-dependencies --libtool --macro-prefix=gl base64 canonicalize chdir close closedir copysign copysignf crypto/md5 dup2 fclose fcntl fflush filemode floor floorf fnmatch fopen fseek ftell getcwd gethostname getopt-gnu gettimeofday glob isatty link lstat malloc-gnu mkdir mkfifo mkostemp mktime nanosleep nproc open opendir pathmax progname readdir readlink realloc-gnu rename rmdir round roundf select sigaction signal sigprocmask sleep stat stdint stdio strerror strftime strptime symlink sys_stat sys_time sys_times time times tmpfile trunc truncf unistd unlink vasprintf
 
 AUTOMAKE_OPTIONS = 1.5 gnits
 
diff --git a/libinterp/corefcn/quadcc.cc b/libinterp/corefcn/quadcc.cc
--- a/libinterp/corefcn/quadcc.cc
+++ b/libinterp/corefcn/quadcc.cc
@@ -1720,7 +1720,7 @@
       Vinvfx (iv->fx, &(iv->c[idx[2]]), 2);
       Vinvfx (iv->fx, &(iv->c[0]), 0);
       for (i = 0; i < nnans; i++)
-        iv->fx[i] = octave_NaN;
+        iv->fx[nans[i]] = octave_NaN;
       iv->a = iivals[j];
       iv->b = iivals[j + 1];
       iv->depth = 3;
@@ -1849,7 +1849,7 @@
             {
               downdate (&(iv->c[idx[d]]), n[d], d, nans, nnans);
               for (i = 0; i < nnans; i++)
-                iv->fx[i] = octave_NaN;
+                iv->fx[nans[i]] = octave_NaN;
             }
 
           /* Compute the error estimate. */
@@ -1994,7 +1994,7 @@
             {
               downdate (ivl->c, n[0], 0, nans, nnans);
               for (i = 0; i < nnans; i++)
-                ivl->fx[i] = octave_NaN;
+                ivl->fx[nans[i]] = octave_NaN;
             }
           for (i = 0; i <= n[d]; i++)
             {
@@ -2090,7 +2090,7 @@
             {
               downdate (ivr->c, n[0], 0, nans, nnans);
               for (i = 0; i < nnans; i++)
-                ivr->fx[i] = octave_NaN;
+                ivr->fx[nans[i]] = octave_NaN;
             }
           for (i = 0; i <= n[d]; i++)
             {
@@ -2255,6 +2255,19 @@
 %!assert (quadcc (@(x) exp (-x .^ 2), -Inf, Inf), sqrt (pi), 1e-6)
 %!assert (quadcc (@(x) exp (-x .^ 2), -Inf, 0), sqrt (pi)/2, 1e-6)
 
+## Test function with NaNs in interval 
+%!function y = __nansin (x)
+%!  nan_locs = [-3*pi/4, -pi/4, 0, pi/3, pi/2, pi];
+%!  y = sin (x);
+%!  idx = min (abs (bsxfun (@minus, x(:), nan_locs)), [], 2); 
+%!  y(idx < 1e-10) = NaN;
+%!endfunction 
+
+%!test
+%! [q, err, npoints] = quadcc ("__nansin", -pi, pi); 
+%! assert (q, 0, eps);
+%! assert (err, 0, 15*eps);
+
 %% Test input validation
 %!error (quadcc ())
 %!error (quadcc (@sin))
diff --git a/libinterp/interpfcn/data.cc b/libinterp/interpfcn/data.cc
--- a/libinterp/interpfcn/data.cc
+++ b/libinterp/interpfcn/data.cc
@@ -1338,6 +1338,11 @@
 %!assert (diag (int8 ([0, 1, 0, 0; 0, 0, 2, 0; 0, 0, 0, 3; 0, 0, 0, 0]), 1), int8 ([1; 2; 3]))
 %!assert (diag (int8 ([0, 0, 0, 0; 1, 0, 0, 0; 0, 2, 0, 0; 0, 0, 3, 0]), -1), int8 ([1; 2; 3]))
 
+## bug #37411
+%!assert (diag (diag ([5, 2, 3])(:,1)), diag([5 0 0 ]))
+%!assert (diag (diag ([5, 2, 3])(:,1), 2),  [0 0 5 0 0; zeros(4, 5)])
+%!assert (diag (diag ([5, 2, 3])(:,1), -2), [[0 0 5 0 0]', zeros(5, 4)])
+
 ## Test non-square size
 %!assert (diag ([1,2,3], 6, 3), [1 0 0; 0 2 0; 0 0 3; 0 0 0; 0 0 0; 0 0 0])
 %!assert (diag (1, 2, 3), [1,0,0; 0,0,0]);
diff --git a/libinterp/interpfcn/utils.cc b/libinterp/interpfcn/utils.cc
--- a/libinterp/interpfcn/utils.cc
+++ b/libinterp/interpfcn/utils.cc
@@ -99,19 +99,17 @@
 @seealso{iskeyword, exist, who}\n\
 @end deftypefn")
 {
-  octave_value retval;
+  octave_value retval = false;
 
-  int argc = args.length () + 1;
-
-  string_vector argv = args.make_argv ("isvarname");
+  int nargin = args.length ();
 
-  if (error_state)
-    return retval;
-
-  if (argc == 2)
-    retval = valid_identifier (argv[1]) && ! is_keyword (argv[1]);
-  else
+  if (nargin != 1)
     print_usage ();
+  else if (args(0).is_string ())
+    {
+      std::string varname = args(0).string_value ();
+      retval = valid_identifier (varname) && ! is_keyword (varname);
+    }
 
   return retval;
 }
@@ -122,6 +120,7 @@
 %!assert (isvarname ("_1"), true)
 %!assert (isvarname ("1foo"), false)
 %!assert (isvarname (""), false)
+%!assert (isvarname (12), false)
 
 %!error isvarname ()
 %!error isvarname ("foo", "bar");
diff --git a/libinterp/octave-value/ov-base-diag.cc b/libinterp/octave-value/ov-base-diag.cc
--- a/libinterp/octave-value/ov-base-diag.cc
+++ b/libinterp/octave-value/ov-base-diag.cc
@@ -68,6 +68,32 @@
   return retval.next_subsref (type, idx);
 }
 
+
+template <class DMT, class MT>
+octave_value
+octave_base_diag<DMT,MT>::diag (octave_idx_type k) const
+{
+  octave_value retval;
+  if (matrix.rows () == 1 || matrix.cols () == 1)
+    {
+      // Rather odd special case. This is a row or column vector
+      // represented as a diagonal matrix with a single nonzero entry, but
+      // Fdiag semantics are to product a diagonal matrix for vector
+      // inputs.
+      if (k == 0)
+        // Returns Diag2Array<T> with nnz <= 1.
+        retval = matrix.build_diag_matrix ();
+      else
+        // Returns Array<T> matrix
+        retval = matrix.array_value ().diag (k);
+    }
+  else
+    // Returns Array<T> vector
+    retval = matrix.extract_diag (k);
+  return retval;
+}
+
+
 template <class DMT, class MT>
 octave_value
 octave_base_diag<DMT, MT>::do_index_op (const octave_value_list& idx,
diff --git a/libinterp/octave-value/ov-base-diag.h b/libinterp/octave-value/ov-base-diag.h
--- a/libinterp/octave-value/ov-base-diag.h
+++ b/libinterp/octave-value/ov-base-diag.h
@@ -97,8 +97,7 @@
   MatrixType matrix_type (const MatrixType&) const
     { return matrix_type (); }
 
-  octave_value diag (octave_idx_type k = 0) const
-    { return octave_value (matrix.diag (k)); }
+  octave_value diag (octave_idx_type k = 0) const;
 
   octave_value sort (octave_idx_type dim = 0, sortmode mode = ASCENDING) const
     { return to_dense ().sort (dim, mode); }
diff --git a/libinterp/octave-value/ov.cc b/libinterp/octave-value/ov.cc
--- a/libinterp/octave-value/ov.cc
+++ b/libinterp/octave-value/ov.cc
@@ -669,6 +669,30 @@
   maybe_mutate ();
 }
 
+octave_value::octave_value (const DiagArray2<double>& d)
+  : rep (new octave_diag_matrix (d))
+{
+  maybe_mutate ();
+}
+
+octave_value::octave_value (const DiagArray2<float>& d)
+  : rep (new octave_float_diag_matrix (d))
+{
+  maybe_mutate ();
+}
+
+octave_value::octave_value (const DiagArray2<Complex>& d)
+  : rep (new octave_complex_diag_matrix (d))
+{
+  maybe_mutate ();
+}
+
+octave_value::octave_value (const DiagArray2<FloatComplex>& d)
+  : rep (new octave_float_complex_diag_matrix (d))
+{
+  maybe_mutate ();
+}
+
 octave_value::octave_value (const DiagMatrix& d)
   : rep (new octave_diag_matrix (d))
 {
diff --git a/libinterp/octave-value/ov.h b/libinterp/octave-value/ov.h
--- a/libinterp/octave-value/ov.h
+++ b/libinterp/octave-value/ov.h
@@ -203,6 +203,10 @@
   octave_value (const Array<double>& m);
   octave_value (const Array<float>& m);
   octave_value (const DiagMatrix& d);
+  octave_value (const DiagArray2<double>& d);
+  octave_value (const DiagArray2<float>& d);
+  octave_value (const DiagArray2<Complex>& d);
+  octave_value (const DiagArray2<FloatComplex>& d);
   octave_value (const FloatDiagMatrix& d);
   octave_value (const RowVector& v);
   octave_value (const FloatRowVector& v);
diff --git a/libinterp/octave.cc b/libinterp/octave.cc
--- a/libinterp/octave.cc
+++ b/libinterp/octave.cc
@@ -675,6 +675,7 @@
 
   bind_internal_variable ("PS1", ">> ");
   bind_internal_variable ("PS2", "");
+  bind_internal_variable ("PS4", "");
   bind_internal_variable ("allow_noninteger_range_as_index", true);
   bind_internal_variable ("beep_on_error", true);
   bind_internal_variable ("confirm_recursive_rmdir", false);
diff --git a/liboctave/array/DiagArray2.cc b/liboctave/array/DiagArray2.cc
--- a/liboctave/array/DiagArray2.cc
+++ b/liboctave/array/DiagArray2.cc
@@ -50,6 +50,13 @@
 Array<T>
 DiagArray2<T>::diag (octave_idx_type k) const
 {
+  return extract_diag (k);
+}
+
+template <class T>
+Array<T>
+DiagArray2<T>::extract_diag (octave_idx_type k) const
+{
   Array<T> d;
 
   if (k == 0)
diff --git a/liboctave/array/DiagArray2.h b/liboctave/array/DiagArray2.h
--- a/liboctave/array/DiagArray2.h
+++ b/liboctave/array/DiagArray2.h
@@ -64,7 +64,7 @@
 
   template <class U>
   DiagArray2 (const DiagArray2<U>& a)
-    : Array<T> (a.diag ()), d1 (a.dim1 ()), d2 (a.dim2 ()) { }
+    : Array<T> (a.extract_diag ()), d1 (a.dim1 ()), d2 (a.dim2 ()) { }
 
   ~DiagArray2 (void) { }
 
@@ -97,7 +97,12 @@
 
   dim_vector dims (void) const { return dim_vector (d1, d2); }
 
-  Array<T> diag (octave_idx_type k = 0) const;
+  Array<T> diag (octave_idx_type k = 0) const GCC_ATTR_DEPRECATED;
+  Array<T> extract_diag (octave_idx_type k = 0) const;
+  DiagArray2<T> build_diag_matrix () const
+  {
+    return DiagArray2<T> (array_value ());
+  }
 
   // Warning: the non-const two-index versions will silently ignore assignments
   // to off-diagonal elements.
diff --git a/scripts/general/repmat.m b/scripts/general/repmat.m
--- a/scripts/general/repmat.m
+++ b/scripts/general/repmat.m
@@ -40,24 +40,48 @@
   endif
 
   if (nargin == 3)
-    if (! (isscalar (m) && isscalar (n)))
-      error ("repmat: with 3 arguments M and N must be scalar");
+    if (! isempty (m) && isempty (n))
+      m = m(:).';
+      n = 1;
+    elseif (isempty (m) && ! isempty (n))
+      m = n(:).';
+      n = 1;
+    elseif (isempty (m) && isempty (n))
+      m = n = 1;
+    else
+      if (all (size (m) > 1))
+        m = m(:,1);
+        if (numel (m) < 3)
+          n = n(end);
+        else
+          n = [];
+        endif
+      endif
+      if (all (size (n) > 1))
+        n = n(:,1);
+      endif
+      m = m(:).';
+      n = n(:).';
     endif
-    idx = [m, n];
   else
-    if (isscalar (m))
-      idx = [m, m];
+    if (isempty (m))
+      m = n = 1;
+    elseif (isscalar (m))
       n = m;
-    elseif (isvector (m) && length (m) > 1)
-      ## Ensure that we have a row vector
-      idx = m(:).';
+    elseif (ndims (m) > 2)
+      error ("repmat: M has more than 2 dimensions")
+    elseif (all (size (m) > 1))
+      m = m(:,1).';
+      n = [];
     else
-      error ("repmat: invalid dimensional argument");
+      m = m(:).';
+      n = [];
     endif
   endif
+  idx = [m, n];
 
   if (all (idx < 0))
-    error ("repmat: invalid dimensions");
+    error ("repmat: invalid dimensions")
   else
     idx = max (idx, 0);
   endif
@@ -101,6 +125,20 @@
 
 endfunction
 
+# Tests for ML compatibility
+%!shared x
+%! x = [1 2 3];
+%!assert (repmat (x, [3, 1]), repmat (x, 3, []))
+%!assert (repmat (x, [3, 1]), repmat (x, [], 3))
+%!assert (repmat (x, [1, 3]), repmat (x, [], [1, 3]))
+%!assert (repmat (x, [1, 3]), repmat (x, [1, 3], []))
+%!assert (repmat (x, [1 3]), repmat (x, [1 3; 3 3]))
+%!assert (repmat (x, [1 1 2]), repmat (x, [1 1; 1 3; 2 1]))
+%!assert (repmat (x, [1 3; 1 3], [1; 3]), repmat (x, [1 1 3]))
+%!assert (repmat (x, [1 1], 4), repmat (x, [1 3; 1 3], [1; 4]))
+%!assert (repmat (x, [1 1], 4), repmat (x, [1 3; 1 3], [1 2; 3 4]))
+%!assert (repmat (x, [1 1], 4), repmat (x, [1 1 4]));
+%!assert (repmat (x, [1 1], 4), repmat (x, 1, [1 4]));
 
 # Test various methods of providing size parameters
 %!shared x
diff --git a/scripts/plot/legend.m b/scripts/plot/legend.m
--- a/scripts/plot/legend.m
+++ b/scripts/plot/legend.m
@@ -26,13 +26,14 @@
 ## @deftypefnx {Function File} {} legend (@var{hobjs}, @dots{})
 ## @deftypefnx {Function File} {} legend (@var{hax}, @var{hobjs}, @dots{})
 ## @deftypefnx {Function File} {} legend ("@var{option}")
+## @deftypefnx {Function File} {[@var{hleg}, @var{hleg_obj}, @var{hplot}, @var{labels}] =} legend (@dots{})
 ##
 ## Display a legend for the axes with handle @var{hax}, or the current axes,
 ## using the specified strings as labels.  Legend entries may be specified
 ## as individual character string arguments, a character array, or a cell
 ## array of character strings.  If the handles, @var{hobjs}, are not specified
 ## then the legend's strings will be associated with the axes' descendants.
-## Legend works on line graphs, bar graphs, etc.
+## @code{legend} works on line graphs, bar graphs, etc.
 ## A plot must exist before legend is called.
 ##
 ## The optional parameter @var{pos} specifies the location of the legend
@@ -74,8 +75,8 @@
 ## @end multitable
 ##
 ## The optional parameter @var{orient} determines if the key elements
-## are placed vertically or horizontally.  The allowed values are "vertical"
-## or "horizontal" with the default being "vertical".
+## are placed vertically or horizontally.  The allowed values are
+## "vertical" (default) or "horizontal".
 ##
 ## The following customizations are available using @var{option}:
 ##
@@ -96,14 +97,35 @@
 ##   Hide the box around legend
 ##
 ## @item "left"
-##   Place text to the left of the keys
+##   Place label text to the left of the keys
 ##
 ## @item "right"
-##   Place text to the right of the keys
+##   Place label text to the right of the keys
 ##
 ## @itemx "off"
 ##   Delete the legend object
 ## @end table
+##
+## The optional output values are
+##
+## @table @var
+## @item hleg
+##   The graphics handle of the legend object.
+##
+## @item hleg_obj
+##   Graphics handles to the text and line objects which make up the legend.
+##
+## @item hplot
+##   Graphics handles to the plot objects which were used in making the legend.
+##
+## @item labels
+##   A cell array of strings of the labels in the legend.
+## @end table 
+##
+## The legend label text is either provided in the call to @code{legend} or
+## is taken from the DisplayName property of graphics objects.  If no
+## labels or DisplayNames are available, then the label text is simply
+## "data1", "data2", @dots{}, "dataN".
 ## @end deftypefn
 
 function [hlegend2, hobjects2, hplot2, text_strings2] = legend (varargin)
@@ -122,6 +144,7 @@
     ca = gca ();
   endif
 
+  ## Special handling for plotyy which has two axes objects
   if (ishandle (ca) && isprop (ca, "__plotyy_axes__"))
     plty = get (ca, "__plotyy_axes__");
     if (isscalar (plty) && ishandle (plty))
@@ -135,7 +158,7 @@
     endif
     ## Remove duplicates while preserving order
     [~, n] = unique (ca);
-    ca = ca (sort (n));
+    ca = ca(sort (n));
   endif
 
   if (nargin > 0 && all (ishandle (varargin{1})))
@@ -143,7 +166,7 @@
     varargin(1) = [];
   else
     kids = ca;
-    kids (strcmp (get (ca, "tag"), "legend")) = [];
+    kids(strcmp (get (ca, "tag"), "legend")) = [];
     if (isscalar (kids))
       kids = get (kids, "children")(:);
     else
@@ -159,6 +182,7 @@
   textpos = "default";
   box = "default";
 
+  ## Process old way of specifying position with a number rather than a string.
   if (nargs > 0)
     pos = varargin{nargs};
     if (isnumeric (pos) && isscalar (pos) && pos == fix (pos))
@@ -172,13 +196,14 @@
     endif
   endif
 
+  ## Find position and orientation property/value pairs
   while (nargs > 1)
     pos = varargin{nargs-1};
     str = varargin{nargs};
-    if (strcmpi (pos, "location")  && ischar (str))
+    if (strcmpi (pos, "location") && ischar (str))
       position = lower (str);
       nargs -= 2;
-    elseif (strcmpi (pos, "orientation")  && ischar (str))
+    elseif (strcmpi (pos, "orientation") && ischar (str))
       orientation = lower (str);
       nargs -= 2;
     else
@@ -188,12 +213,12 @@
 
   ## Validate the orientation
   switch (orientation)
-    case {"vertical", "horizontal","default"}
+    case {"vertical", "horizontal", "default"}
     otherwise
       error ("legend: unrecognized legend orientation");
   endswitch
 
-  ## Validate the position type is valid
+  ## Validate the position type
   outside = false;
   inout = strfind (position, "outside");
   if (! isempty (inout))
@@ -213,14 +238,15 @@
       error ("legend: unrecognized legend position");
   endswitch
 
+  ## Find any existing legend object on figure
   hlegend = [];
   fkids = get (fig, "children");
   for i = 1 : numel (fkids)
-    if (ishandle (fkids (i)) && strcmp (get (fkids (i), "type"), "axes")
-        && (strcmp (get (fkids (i), "tag"), "legend")))
-      udata = get (fkids (i), "userdata");
+    if (ishandle (fkids(i)) && strcmp (get (fkids(i), "type"), "axes")
+        && (strcmp (get (fkids(i), "tag"), "legend")))
+      udata = get (fkids(i), "userdata");
       if (! isempty (intersect (udata.handle, ca)))
-        hlegend = fkids (i);
+        hlegend = fkids(i);
         break;
       endif
     endif
@@ -230,19 +256,27 @@
     arg = varargin{1};
     if (ischar (arg))
       if (rows (arg) == 1)
-        str = tolower (deblank (arg));
+        str = tolower (strtrim (arg));
         switch (str)
-          case {"off"}
+          case "off"
             delete (hlegend);
-            return
-          case {"hide"}
+            return;
+          case "hide"
             show = "off";
             nargs--;
           case "show"
-            show = "on";
+            if (! isempty (hlegend))
+              show = "on";
+            else
+              show = "create";
+              textpos = "left";
+            endif
             nargs--;
           case "toggle"
-            if (isempty (hlegend) || strcmp (get (hlegend, "visible"), "off"))
+            if (isempty (hlegend))
+              show = "create";
+              textpos = "left";
+            elseif (strcmp (get (hlegend, "visible"), "off"))
               show = "on";
             else
               show = "off";
@@ -260,23 +294,27 @@
           case "right"
             textpos = "right";
             nargs--;
-          otherwise
         endswitch
       else
+        ## Character matrix of labels
         varargin = cellstr (arg);
         nargs = numel (varargin);
       endif
     elseif (iscellstr (arg))
+      ## Cell array of labels
       varargin = arg;
       nargs = numel (varargin);
     else
       error ("legend: expecting argument to be a character string");
     endif
   elseif (nargs > 1 && iscellstr (varargin{1}))
+    ## Cell array of labels followed by property/value pairs
     varargin = {varargin{1}{:}, varargin{2:end}};
     nargs = numel (varargin);
   endif
 
+  have_labels = (nargs > 0);
+
   if (strcmp (show, "off"))
     if (! isempty (hlegend))
       set (findobj (hlegend), "visible", "off");
@@ -297,14 +335,15 @@
     endif
   elseif (strcmp (box, "on"))
     if (! isempty (hlegend))
-      set (hlegend, "visible", "on", "box", "on");
+      set (hlegend, "box", "on", "visible", "on");
     endif
   elseif (strcmp (box, "off"))
     if (! isempty (hlegend))
       set (hlegend, "box", "off", "visible", "off");
     endif
-  elseif (nargs == 0 && !(strcmp (position, "default") &&
-                          strcmp (orientation, "default")))
+  elseif (! have_labels && !(strcmp (position, "default") &&
+                             strcmp (orientation, "default")))
+    ## Changing location or orientation of existing legend
     if (! isempty (hlegend))
       hax = getfield (get (hlegend, "userdata"), "handle");
       [hplots, text_strings] = __getlegenddata__ (hlegend);
@@ -329,13 +368,16 @@
       endif
     endif
   else
+    ## Create new legend
     hobjects = [];
     hplots  = [];
     text_strings = {};
 
-    if (nargs > 0)
+    if (have_labels)
+      ## Check for valid data that can be labeled.
       have_data = false;
-      for k = 1:nkids
+      have_dname = false;
+      for k = 1 : nkids
         typ = get (kids(k), "type");
         if (strcmp (typ, "line") || strcmp (typ, "surface")
             || strcmp (typ, "patch") || strcmp (typ, "hggroup"))
@@ -347,11 +389,40 @@
       if (! have_data)
         warning ("legend: plot data is empty; setting key labels has no effect");
       endif
-    endif
+    else
+      ## No labels.  Search for DisplayName property.
+      have_dname = false;
+      for k = 1 : nkids
+        hkid = kids(k);
+        typ = get (hkid, "type");
+        if (strcmp (typ, "line") || strcmp (typ, "surface")
+            || strcmp (typ, "patch"))
+          if (! isempty (get (hkid, "displayname")))
+            have_dname = true;
+            break;
+          endif
+        elseif (strcmp (typ, "hggroup"))
+          hgkids = get (hkid, "children");
+          for j = 1 : length (hgkids)
+            hgobj = get (hgkids(j));
+            if (isfield (hgobj, "displayname") && ! isempty (hgobj.displayname))
+              have_dname = true;
+              break;  # break from j-loop over hgkids
+            endif
+          endfor
+          if (have_dname)
+            break;  # break from k loop over nkids
+          endif
+        endif  # elseif hggroup
+      endfor   # for loop k = 1 : nkids
+    endif      # else branch of if (have_labels)
 
-    if (strcmp (textpos, "default"))
-      warned = false;
+    if (have_labels || ! have_dname)
       k = nkids;
+      if (! have_labels)
+        varargin = arrayfun (@(x) sprintf ("data%d", x), [1:nkids]', "uniformoutput", false);
+        nargs = nkids;
+      endif
       for i = 1 : nargs
         arg = varargin{i};
         if (ischar (arg))
@@ -365,16 +436,20 @@
             if (strcmp (get (kids(k), "type"), "hggroup"))
               hgkids = get (kids(k), "children");
               for j = 1 : length (hgkids)
-                hgobj = get (hgkids (j));
+                hgobj = get (hgkids(j));
                 if (isfield (hgobj, "displayname"))
-                  set (hgkids(j), "displayname", arg);
+                  if (have_labels)
+                    set (hgkids(j), "displayname", arg);
+                  endif
                   hplots = [hplots, hgkids(j)];
                   text_strings = {text_strings{:}, arg};
                   break;
                 endif
               endfor
             else
-              set (kids(k), "displayname", arg);
+              if (have_labels)
+                set (kids(k), "displayname", arg);
+              endif
               hplots = [hplots, kids(k)];
               text_strings = {text_strings{:}, arg};
             endif
@@ -382,17 +457,18 @@
             if (--k == 0)
               break;
             endif
-          elseif (! warned)
-            break;
+          else
+            break;  # k = 0, no further handles to process
           endif
         else
           error ("legend: expecting argument to be a character string");
         endif
       endfor
-      if (i < nargs && ! warned)
+      if (have_labels && i < nargs)
         warning ("legend: ignoring extra labels");
       endif
     else
+      ## No labels specified but objects have DisplayName property set.
       k = nkids;
       while (k > 0)
         typ = get (kids(k), "type");
@@ -409,7 +485,7 @@
           if (strcmp (get (kids(k), "type"), "hggroup"))
             hgkids = get (kids(k), "children");
             for j = 1 : length (hgkids)
-              hgobj = get (hgkids (j));
+              hgobj = get (hgkids(j));
               if (isfield (hgobj, "displayname")
                   && ! isempty (hgobj.displayname))
                 hplots = [hplots, hgkids(j)];
@@ -418,9 +494,9 @@
               endif
             endfor
           else
-            if (! isempty (get (kids (k), "displayname")))
+            if (! isempty (get (kids(k), "displayname")))
               hplots = [hplots, kids(k)];
-              text_strings = {text_strings{:}, get(kids (k), "displayname")};
+              text_strings = {text_strings{:}, get(kids(k), "displayname")};
             endif
           endif
           if (--k == 0)
@@ -433,7 +509,7 @@
     if (isempty (hplots))
       if (! isempty (hlegend))
         fkids = get (fig, "children");
-        delete (fkids (fkids == hlegend));
+        delete (fkids(fkids == hlegend));
         hlegend = [];
         hobjects = [];
         hplots  = [];
@@ -524,24 +600,24 @@
         maxheight = 0;
         for k = 1 : nentries
           if (strcmp (textpos, "right"))
-            texthandle = [texthandle, text(0, 0, text_strings {k},
+            texthandle = [texthandle, text(0, 0, text_strings{k},
                                            "horizontalalignment", "left",
                                            "userdata", hplots(k),
                                            "fontsize", ca_fontsize)];
           else
-            texthandle = [texthandle, text(0, 0, text_strings {k},
+            texthandle = [texthandle, text(0, 0, text_strings{k},
                                            "horizontalalignment", "right",
                                            "userdata", hplots(k),
                                            "fontsize", ca_fontsize)];
           endif
-          units = get (texthandle (end), "units");
+          units = get (texthandle(end), "units");
           unwind_protect
-            set (texthandle (end), "units", "points");
-            extents = get (texthandle (end), "extent");
-            maxwidth = max (maxwidth, extents (3));
-            maxheight = max (maxheight, extents (4));
+            set (texthandle(end), "units", "points");
+            extents = get (texthandle(end), "extent");
+            maxwidth = max (maxwidth, extents(3));
+            maxheight = max (maxheight, extents(4));
           unwind_protect_cleanup
-            set (texthandle (end), "units", units);
+            set (texthandle(end), "units", units);
           end_unwind_protect
         endfor
 
@@ -549,24 +625,24 @@
         if (strcmp (orientation, "vertical"))
           height = nentries * (ypad + maxheight);
           if (outside)
-            if (height > ca_pos (4))
+            if (height > ca_pos(4))
               ## Avoid shrinking the height of the axis to zero if outside
               num1 = ca_pos(4) / (maxheight + ypad) / 2;
             endif
           else
-            if (height > 0.9 * ca_pos (4))
+            if (height > 0.9 * ca_pos(4))
               num1 = 0.9 * ca_pos(4) / (maxheight + ypad);
             endif
           endif
         else
           width = nentries * (ypad + maxwidth);
           if (outside)
-            if (width > ca_pos (3))
+            if (width > ca_pos(3))
               ## Avoid shrinking the width of the axis to zero if outside
               num1 = ca_pos(3) / (maxwidth + ypad) / 2;
             endif
           else
-            if (width > 0.9 * ca_pos (3))
+            if (width > 0.9 * ca_pos(3))
               num1 = 0.9 * ca_pos(3) / (maxwidth + ypad);
             endif
           endif
@@ -683,7 +759,7 @@
         xk = 0;
         yk = 0;
         for k = 1 : numel (hplots)
-          hobjects = [hobjects, texthandle (k)];
+          hobjects = [hobjects, texthandle(k)];
           switch (get (hplots(k), "type"))
           case "line"
             color = get (hplots(k), "color");
@@ -724,7 +800,7 @@
                          "ydata", (lpos(4) - yoffset -
                                    [yk-0.3, yk-0.3, yk+0.3, yk+0.3] .* ystep) / lpos(4),
                          "facecolor", facecolor, "edgecolor", edgecolor, "cdata", cdata,
-                         "userdata", hplots (k));
+                         "userdata", hplots(k));
               hobjects = [hobjects, p1];
             endif
           case "surface"
@@ -753,16 +829,16 @@
                    "xliminclude", "off", "yliminclude", "off");
         set (t1, "deletefcn", {@deletelegend1, hlegend});
 
-        ## Resize the axis the legend is attached to if the
-        ## legend is "outside" the plot and create listener to
+        ## Resize the axis that the legend is attached to if the
+        ## legend is "outside" the plot and create a listener to
         ## resize axis to original size if the legend is deleted,
-        ## hidden or shown
+        ## hidden, or shown.
         if (outside)
           for i = 1 : numel (ca)
             units = get (ca(i), "units");
             unwind_protect
               set (ca(i), "units", "points");
-              set (ca (i), "position", new_pos);
+              set (ca(i), "position", new_pos);
             unwind_protect_cleanup
               set (ca(i), "units", units);
             end_unwind_protect
@@ -875,7 +951,7 @@
 
 function deletelegend1 (h, d, ca)
   if (ishandle (ca) && strcmp (get (ca, "type"), "axes")
-      && (isempty (gcbf ()) || strcmp (get (gcbf (), "beingdeleted"),"off"))
+      && (isempty (gcbf ()) || strcmp (get (gcbf (), "beingdeleted"), "off"))
       && strcmp (get (ca, "beingdeleted"), "off"))
     delete (ca);
   endif
@@ -884,7 +960,7 @@
 function deletelegend2 (h, d, ca, pos, outpos, t1, hplots)
   for i = 1 : numel (ca)
     if (ishandle (ca(i)) && strcmp (get (ca(i), "type"), "axes")
-        && (isempty (gcbf ()) || strcmp (get (gcbf (), "beingdeleted"),"off"))
+        && (isempty (gcbf ()) || strcmp (get (gcbf (), "beingdeleted"), "off"))
         && strcmp (get (ca(i), "beingdeleted"), "off"))
       if (!isempty (pos) && !isempty(outpos))
         units = get (ca(i), "units");
@@ -900,14 +976,14 @@
   set (t1, "deletefcn", "");
   delete (t1);
   for i = 1 : numel (hplots)
-    if (strcmp (get (hplots (i), "type"), "line"))
-      dellistener (hplots (i), "color");
-      dellistener (hplots (i), "linestyle");
-      dellistener (hplots (i), "marker");
-      dellistener (hplots (i), "markeredgecolor");
-      dellistener (hplots (i), "markerfacecolor");
-      dellistener (hplots (i), "markersize");
-      dellistener (hplots (i), "displayname");
+    if (strcmp (get (hplots(i), "type"), "line"))
+      dellistener (hplots(i), "color");
+      dellistener (hplots(i), "linestyle");
+      dellistener (hplots(i), "marker");
+      dellistener (hplots(i), "markeredgecolor");
+      dellistener (hplots(i), "markerfacecolor");
+      dellistener (hplots(i), "markersize");
+      dellistener (hplots(i), "displayname");
     endif
   endfor
 endfunction
@@ -917,12 +993,12 @@
   ll = [];
   kids = get (hlegend, "children");
   for i = 1 : numel (kids)
-    if (get (kids (i), "userdata") == h
+    if (get (kids(i), "userdata") == h
         && strcmp (get (kids(i), "type"), "line"))
       if (strcmp (get (kids (i), "marker"), "none"))
-        ll = kids (i);
+        ll = kids(i);
       else
-        lm = kids (i);
+        lm = kids(i);
       endif
     endif
   endfor
@@ -938,7 +1014,7 @@
     ## legend function to recreate a new legend
     [hplots, text_strings] = __getlegenddata__ (hlegend);
     for i = 1 : numel (hplots)
-      if (hplots (i) == h)
+      if (hplots(i) == h)
         hplots(i) = [];
         text_strings(i) = [];
         break;
@@ -986,39 +1062,22 @@
   endif
 endfunction
 
-%!demo
-%! plot (rand (2))
-%! legend ({'foo'}, 'bar', 'boxoff')
-%! title ('legend() should warn about an extra label')
-
-%!demo
-%! plot (rand (2,2)) ;
-%! h = legend ('a', 'b') ;
-%! legend ('right') ;
-%! set (h, 'textposition', 'left')
-%! set (h, 'textposition', 'right')
-%! set (h, 'textcolor', [1 0 1])
 
 %!demo
-%! clf;
-%! x = 0:1;
-%! plot (x,x,';I am Blue;', x,2*x,';I am Green;', x,3*x,';I am Red;');
-%! legend boxon
-%! legend hide
-%! legend show
+%! plot (rand (2));
+%! title ('legend called with cellstr and string inputs for labels');
+%! legend ({'foo'}, 'bar');
 
 %!demo
-%! clf;
-%! x = 0:1;
-%! plot (x, x, ';\alpha;',  ...
-%!       x, 2*x, ';\beta=2\alpha;',  ...
-%!       x, 3*x, ';\gamma=3\alpha;');
+%! plot (rand (3));
+%! title ('legend() without inputs creates default labels');
+%! legend ();
 
 %!demo
 %! clf;
 %! x = 0:1;
 %! plot (x,x,';I am Blue;', x,2*x, x,3*x,';I am Red;');
-%! title ('Blue and Green keys, with Green missing');
+%! title ('Blue and Red keys, with Green missing');
 
 %!demo
 %! clf;
@@ -1029,9 +1088,9 @@
 %!demo
 %! clf;
 %! plot (1:10, 1:10, 1:10, fliplr (1:10));
-%! title ('Legend is hidden')
-%! legend ({'I am blue', 'I am green'}, 'location', 'east');
-%! legend hide;
+%! title ('Legend with keys in horizontal orientation');
+%! legend ({'I am blue', 'I am green'}, 'location', 'east', 'orientation', 'horizontal');
+%! legend boxoff;
 
 %!demo
 %! clf;
@@ -1043,21 +1102,55 @@
 %!demo
 %! clf;
 %! plot (1:10, 1:10, 1:10, fliplr (1:10));
-%! title ('Legend with text to the right');
+%! title ('Legend with text to the right of key');
 %! legend ({'I am blue', 'I am green'}, 'location', 'east');
 %! legend right;
 
 %!demo
 %! clf;
+%! plot (1:10, 1:10, 1:10, fliplr (1:10));
+%! title ('Using properties to have legend text shown to the right of key');
+%! h = legend ({'I am blue', 'I am green'}, 'location', 'east');
+%! legend ('left');
+%! set (h, 'textposition', 'right');
+%! set (h, 'textcolor', [1 0 1]);
+
+%!demo
+%! clf;
+%! plot (1:10, 1:10, 1:10, fliplr (1:10));
+%! title ('Legend is hidden')
+%! legend ({'I am blue', 'I am green'}, 'location', 'east');
+%! legend hide;
+
+%!demo
+%! clf;
+%! x = 0:1;
+%! plot (x,x,';I am Blue;', x,2*x,';I am Green;', x,3*x,';I am Red;');
+%! title ('labels embedded in call to plot');
+%! legend boxon
+%! legend hide
+%! legend show
+
+%!demo
+%! clf;
+%! x = 0:1;
+%! plot (x, x, ';\alpha;',  ...
+%!       x, 2*x, ';\beta=2\alpha;',  ...
+%!       x, 3*x, ';\gamma=3\alpha;');
+%! title ('labels with interpreted Greek text');
+
+%!demo
+%! clf;
+%! plot (rand (2));
+%! title ('Labels with TeX interpreter turned off');
+%! h = legend ('Hello_World', 'foo^bar');
+%! set (h, 'interpreter', 'none');
+
+%!demo
+%! clf;
 %! plot (1:10, 1:10);
 %! title ('a very long label can sometimes cause problems');
-%! legend ({'hello world'}, 'location', 'northeastoutside');
-
-%!demo
-%! clf;
-%! plot (1:10, 1:10);
-%! title ('a very long label can sometimes cause problems');
-%! legend ('hello world', 'location', 'northeastoutside');
+%! legend ('hello very big world', 'location', 'northeastoutside');
 
 %!demo
 %! clf;
@@ -1069,7 +1162,8 @@
 %!   labels = {labels{:}, ['Signal ', num2str(i)]};
 %! end
 %! hold off;
-%! title ('Signals with random offset and uniform noise');
+%! title ({'Signals with random offset and uniform noise';
+%!         'Legend shown below and outside of plot'});
 %! xlabel ('Sample Nr [k]'); ylabel ('Amplitude [V]');
 %! legend (labels, 'location', 'southoutside');
 
@@ -1079,6 +1173,7 @@
 %! plot (x, x);
 %! hold on;
 %! stem (x, x.^2, 'g');
+%! title ('First created object gets first label');
 %! legend ('linear');
 %! hold off;
 
@@ -1086,12 +1181,14 @@
 %! clf;
 %! x = linspace (0, 10);
 %! plot (x, x, x, x.^2);
+%! title ('First created object gets first label');
 %! legend ('linear');
 
 %!demo
 %! clf;
 %! x = linspace (0, 10);
 %! plot (x, x, x, x.^2);
+%! title ('Labels are applied in order of object creation');
 %! legend ('linear', 'quadratic');
 
 %!demo
@@ -1099,6 +1196,7 @@
 %! rand_2x3_data1 = [0.341447, 0.171220, 0.284370; 0.039773, 0.731725, 0.779382];
 %! bar (rand_2x3_data1);
 %! ylim ([0 1.0]);
+%! title ('legend() works for bar graphs (hgobjects)');
 %! legend ({'1st Bar', '2nd Bar', '3rd Bar'});
 
 %!demo
@@ -1106,6 +1204,7 @@
 %! rand_2x3_data2 = [0.44804, 0.84368, 0.23012; 0.72311, 0.58335, 0.90531];
 %! bar (rand_2x3_data2);
 %! ylim ([0 1.2]);
+%! title ('legend() works for bar graphs (hgobjects)');
 %! legend ('1st Bar', '2nd Bar', '3rd Bar');
 %! legend right;
 
@@ -1123,6 +1222,7 @@
 %! hold all;
 %! plot (x, cos (x), ';cos (x);');
 %! hold off;
+%! title ('legend constructed from multiple plot calls');
 
 %!demo
 %! clf;
@@ -1131,7 +1231,8 @@
 %! hold all;
 %! plot (x, cos (x), ';cos (x);');
 %! hold off;
-%! legend ({'sin (x)', 'cos (x)'}, 'location', 'northeastoutside');
+%! title ('Specified label text overrides previous labels');
+%! legend ({'Sine', 'Cosine'}, 'location', 'northeastoutside');
 
 %!demo
 %! clf;
@@ -1139,7 +1240,7 @@
 %! plot (x, rand (11));
 %! xlabel ('Indices');
 %! ylabel ('Random Values');
-%! title ('Legend ''off'' should delete the legend');
+%! title ('Legend ''off'' deletes the legend');
 %! legend (cellstr (num2str ((1:10)')), 'location', 'northeastoutside');
 %! legend off;
 %! axis ([0, 10, 0 1]);
@@ -1163,21 +1264,15 @@
 %!demo
 %! clf;
 %! plot (rand (2));
-%! title ('Warn of extra labels');
+%! title ('legend() will warn if extra labels are specified');
 %! legend ('Hello', 'World', 'interpreter', 'foobar');
 
 %!demo
-%! clf;
-%! plot (rand (2));
-%! title ('Turn off TeX interpreter');
-%! h = legend ('Hello_World', 'foo^bar');
-%! set (h, 'interpreter', 'none');
-
-%!demo
 %! x = 0:10;
 %! y1 = rand (size (x));
 %! y2 = rand (size (x));
 %! [ax, h1, h2] = plotyy (x, y1, x, y2);
+%! title ('plotyy legend test #1: Blue and Green labels');
 %! legend ([h1, h2], {'Blue', 'Green'}, 'location', 'south');
 
 %!demo
@@ -1185,6 +1280,7 @@
 %! y1 = rand (size (x));
 %! y2 = rand (size (x));
 %! [ax, h1, h2] = plotyy (x, y1, x, y2);
+%! title ('plotyy legend test #2: Blue and Green labels');
 %! legend ({'Blue', 'Green'}, 'location', 'south');
 
 %!demo
@@ -1192,5 +1288,6 @@
 %! y1 = rand (size (x));
 %! y2 = rand (size (x));
 %! [ax, h1, h2] = plotyy (x, y1, x, y2);
+%! title ('plotyy legend test #3: Blue and Green labels');
 %! legend ('Blue', 'Green', 'location', 'south');
 
diff --git a/scripts/plot/private/__go_draw_axes__.m b/scripts/plot/private/__go_draw_axes__.m
--- a/scripts/plot/private/__go_draw_axes__.m
+++ b/scripts/plot/private/__go_draw_axes__.m
@@ -442,6 +442,16 @@
 
       obj = get (kids(end));
 
+      if (isfield (obj, "xdata"))
+        obj.xdata = double (obj.xdata);
+      end
+      if (isfield (obj, "ydata"))
+        obj.ydata = double (obj.ydata);
+      end
+      if (isfield (obj, "zdata"))
+        obj.zdata = double (obj.zdata);
+      end
+
       if (isfield (obj, "units"))
         units = obj.units;
         unwind_protect