X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=octave_packages%2Fm%2Fplot%2Flegend.m;fp=octave_packages%2Fm%2Fplot%2Flegend.m;h=3918cb39d414ac6904ae793901f1f3d0ca6294ef;hp=0000000000000000000000000000000000000000;hb=1c0469ada9531828709108a4882a751d2816994a;hpb=63de9f36673d49121015e3695f2c336ea92bc278

diff --git a/octave_packages/m/plot/legend.m b/octave_packages/m/plot/legend.m
new file mode 100644
index 0000000..3918cb3
--- /dev/null
+++ b/octave_packages/m/plot/legend.m
@@ -0,0 +1,1161 @@
+## Copyright (C) 2010-2012 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/>.
+
+## -*- texinfo -*-
+## @deftypefn  {Function File} {} legend (@var{str1}, @var{str2}, @dots{})
+## @deftypefnx {Function File} {} legend (@var{matstr})
+## @deftypefnx {Function File} {} legend (@var{cell})
+## @deftypefnx {Function File} {} legend (@dots{}, "location", @var{pos})
+## @deftypefnx {Function File} {} legend (@dots{}, "orientation", @var{orient})
+## @deftypefnx {Function File} {} legend (@var{hax}, @dots{})
+## @deftypefnx {Function File} {} legend (@var{hobjs}, @dots{})
+## @deftypefnx {Function File} {} legend (@var{hax}, @var{hobjs}, @dots{})
+## @deftypefnx {Function File} {} legend ("@var{option}")
+##
+## 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.
+## A plot must exist before legend is called.
+##
+## The optional parameter @var{pos} specifies the location of the legend
+## as follows:
+##
+## @multitable @columnfractions 0.06 0.14 0.80
+##
+## @headitem @tab @var{pos} @tab
+##   location of the legend
+##
+## @item @tab north @tab
+##   center top
+##
+## @item @tab south @tab
+##   center bottom
+##
+## @item @tab east @tab
+##   right center
+##
+## @item @tab west @tab
+##   left center
+##
+## @item @tab northeast @tab
+##   right top (default)
+##
+## @item @tab northwest @tab
+##   left top
+##
+## @item @tab southeast @tab
+##   right bottom
+##
+## @item @tab southwest @tab
+##   left bottom
+##
+## @item
+##
+## @item @tab outside @tab
+##   can be appended to any location string
+## @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".
+##
+## The following customizations are available using @var{option}:
+##
+## @table @asis
+## @item "show"
+##   Show legend on the plot
+##
+## @item "hide"
+##   Hide legend on the plot
+##
+## @itemx "toggle"
+##   Toggles between "hide" and "show"
+##
+## @item "boxon"
+##   Show a box around legend
+##
+## @item "boxoff"
+##   Hide the box around legend
+##
+## @item "left"
+##   Place text to the left of the keys
+##
+## @item "right"
+##   Place text to the right of the keys
+##
+## @itemx "off"
+##   Delete the legend object
+## @end table
+## @end deftypefn
+
+function [hlegend2, hobjects2, hplot2, text_strings2] = legend (varargin)
+
+  if (nargin > 0
+      && (! ishandle (varargin{1})
+          || (strcmp (get (varargin{1}, "type"), "axes")
+              && ! strcmp (get (varargin{1}, "tag"), "legend"))))
+    [ca, varargin, nargs] = __plt_get_axis_arg__ ("legend", varargin{:});
+    fig = get (ca, "parent");
+  else
+    fig = get (0, "currentfigure");
+    if (isempty (fig))
+      fig = gcf ();
+    endif
+    ca = gca ();
+  endif
+
+  if (ishandle (ca) && isprop (ca, "__plotyy_axes__"))
+    plty = get (ca, "__plotyy_axes__");
+    if (isscalar (plty) && ishandle (plty))
+      ca = [ca, plty];
+    elseif (iscell (plty))
+      ca = [ca, plty{:}];
+    elseif (all (ishandle (plty)))
+      ca = [ca, plty(:).'];
+    else
+      error ("legend.m: This should not happen. File a bug report.")
+    endif
+    ## Remove duplicates while preserving order
+    [~, n] = unique (ca);
+    ca = ca (sort (n));
+  endif
+
+  if (nargin > 0 && all (ishandle (varargin{1})))
+    kids = flipud (varargin{1}(:));
+    varargin(1) = [];
+  else
+    kids = ca;
+    kids (strcmp (get (ca, "tag"), "legend")) = [];
+    if (isscalar (kids))
+      kids = get(kids, "children")(:);
+    else
+      kids = [get(kids, "children"){:}](:);
+    endif
+  endif
+  nargs = numel (varargin);
+  nkids = numel (kids);
+
+  orientation = "default";
+  position = "default";
+  show = "create";
+  textpos = "default";
+  box = "default";
+
+  if (nargs > 0)
+    pos = varargin{nargs};
+    if (isnumeric (pos) && isscalar (pos) && pos == fix (pos))
+      if (pos >= -1 && pos <= 4)
+        position = [{"northeastoutside", "best", "northeast",
+                     "northwest", "southwest", "southeast"}] {pos + 2};
+        nargs--;
+      else
+        error ("legend: invalid position specified");
+      endif
+    endif
+  endif
+
+  while (nargs > 1)
+    pos = varargin{nargs-1};
+    str = varargin{nargs};
+    if (strcmpi (pos, "location")  && ischar (str))
+      position = lower (str);
+      nargs -= 2;
+    elseif (strcmpi (pos, "orientation")  && ischar (str))
+      orientation = lower (str);
+      nargs -= 2;
+    else
+      break;
+    endif
+  endwhile
+
+  ## Validate the orientation
+  switch (orientation)
+    case {"vertical", "horizontal","default"}
+    otherwise
+      error ("legend: unrecognized legend orientation");
+  endswitch
+
+  ## Validate the position type is valid
+  outside = false;
+  inout = findstr (position, "outside");
+  if (! isempty (inout))
+    outside = true;
+    position = position(1:inout-1);
+  else
+    outside = false;
+  endif
+
+  switch (position)
+    case {"north", "south", "east", "west", "northeast", "northwest", ...
+          "southeast", "southwest", "default"}
+    case "best"
+      warning ("legend: 'Best' not yet implemented for location specifier\n");
+      position = "northeast";
+    otherwise
+      error ("legend: unrecognized legend position");
+  endswitch
+
+  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 (! isempty (intersect (udata.handle, ca)))
+        hlegend = fkids (i);
+        break;
+      endif
+    endif
+  endfor
+
+  if (nargs == 1)
+    arg = varargin{1};
+    if (ischar (arg))
+      if (rows (arg) == 1)
+        str = tolower (deblank (arg));
+        switch (str)
+          case {"off"}
+            delete (hlegend);
+            return
+          case {"hide"}
+            show = "off";
+            nargs--;
+          case "show"
+            show = "on";
+            nargs--;
+          case "toggle"
+            if (isempty (hlegend) || strcmp (get (hlegend, "visible"), "off"))
+              show = "on";
+            else
+              show = "off";
+            endif
+            nargs--;
+          case "boxon"
+            box = "on";
+            nargs--;
+          case "boxoff"
+            box = "off";
+            nargs--;
+          case "left"
+            textpos = "left";
+            nargs--;
+          case "right"
+            textpos = "right";
+            nargs--;
+          otherwise
+        endswitch
+      else
+        varargin = cellstr (arg);
+        nargs = numel (varargin);
+      endif
+    elseif (iscellstr (arg))
+      varargin = arg;
+      nargs = numel (varargin);
+    else
+      error ("legend: expecting argument to be a character string");
+    endif
+  endif
+
+  if (strcmp (show, "off"))
+    if (! isempty (hlegend))
+      set (get (hlegend, "children"), "visible", "off");
+      hlegend = [];
+    endif
+    hobjects = [];
+    hplots  = [];
+    text_strings = {};
+  elseif (strcmp (show, "on"))
+    if (! isempty (hlegend))
+      set (get (hlegend, "children"), "visible", "on");
+    else
+      hobjects = [];
+      hplots  = [];
+      text_strings = {};
+    endif
+  elseif (strcmp (box, "on"))
+    if (! isempty (hlegend))
+      set (hlegend, "visible", "on", "box", "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")))
+    if (! isempty (hlegend))
+      hax = getfield (get (hlegend, "userdata"), "handle");
+      [hplots, text_strings] = __getlegenddata__ (hlegend);
+
+      if  (strcmp (position, "default"))
+        h = legend (hax, hplots, text_strings, "orientation", orientation);
+      elseif (strcmp (orientation, "default"))
+        if (outside)
+          h = legend (hax, hplots, text_strings, "location",
+                      strcat (position, "outside"));
+        else
+          h = legend (hax, hplots, text_strings, "location", position);
+        endif
+      else
+        if (outside)
+          h = legend (hax, hplots, text_strings, "location",
+                      strcat (position, "outside"), "orientation", orientation);
+        else
+          h = legend (hax, hplots, text_strings, "location", position,
+                      "orientation", orientation);
+        endif
+      endif
+    endif
+  else
+    hobjects = [];
+    hplots  = [];
+    text_strings = {};
+
+    if (nargs > 0)
+      have_data = false;
+      for k = 1:nkids
+        typ = get (kids(k), "type");
+        if (strcmp (typ, "line") || strcmp (typ, "surface")
+            || strcmp (typ, "patch") || strcmp (typ, "hggroup"))
+          have_data = true;
+          break;
+        endif
+      endfor
+
+      if (! have_data)
+        warning ("legend: plot data is empty; setting key labels has no effect");
+      endif
+    endif
+
+    if (strcmp (textpos, "default"))
+      warned = false;
+      k = nkids;
+      for i = 1 : nargs
+        arg = varargin{i};
+        if (ischar (arg))
+          typ = get (kids(k), "type");
+          while (k > 0
+                 && ! (strcmp (typ, "line") || strcmp (typ, "surface")
+                       || strcmp (typ, "patch") || strcmp (typ, "hggroup")))
+            typ = get (kids(--k), "type");
+          endwhile
+          if (k > 0)
+            if (strcmp (get (kids(k), "type"), "hggroup"))
+              hgkids = get (kids(k), "children");
+              for j = 1 : length (hgkids)
+                hgobj = get (hgkids (j));
+                if (isfield (hgobj, "displayname"))
+                  set (hgkids(j), "displayname", arg);
+                  hplots = [hplots, hgkids(j)];
+                  text_strings = {text_strings{:}, arg};
+                  break;
+                endif
+              endfor
+            else
+              set (kids(k), "displayname", arg);
+              hplots = [hplots, kids(k)];
+              text_strings = {text_strings{:}, arg};
+            endif
+
+            if (--k == 0)
+              break;
+            endif
+          elseif (! warned)
+            break;
+          endif
+        else
+          error ("legend: expecting argument to be a character string");
+        endif
+      endfor
+      if (i < nargs && ! warned)
+        warning ("legend: ignoring extra labels");
+      endif
+    else
+      k = nkids;
+      while (k > 0)
+        typ = get (kids(k), "type");
+        while (k > 1
+               && ! (strcmp (typ, "line") || strcmp (typ, "surface")
+                     || strcmp (typ, "patch") || strcmp (typ, "hggroup")))
+          typ = get (kids(--k), "type");
+        endwhile
+        if (! (strcmp (typ, "line") || strcmp (typ, "surface")
+               || strcmp (typ, "patch") || strcmp (typ, "hggroup")))
+          break
+        endif
+        if (k > 0)
+          if (strcmp (get (kids(k), "type"), "hggroup"))
+            hgkids = get (kids(k), "children");
+            for j = 1 : length (hgkids)
+              hgobj = get (hgkids (j));
+              if (isfield (hgobj, "displayname")
+                  && ! isempty (hgobj.displayname))
+                hplots = [hplots, hgkids(j)];
+                text_strings = {text_strings{:}, hgobj.displayname};
+                break;
+              endif
+            endfor
+          else
+            if (! isempty (get (kids (k), "displayname")))
+              hplots = [hplots, kids(k)];
+              text_strings = {text_strings{:}, get(kids (k), "displayname")};
+            endif
+          endif
+          if (--k == 0)
+            break;
+          endif
+        endif
+      endwhile
+    endif
+
+    if (isempty (hplots))
+      if (! isempty (hlegend))
+        fkids = get (fig, "children");
+        delete (fkids (fkids == hlegend));
+        hlegend = [];
+        hobjects = [];
+        hplots  = [];
+        text_strings = {};
+      endif
+    else
+      ## Delete the old legend if it exists
+      if (! isempty (hlegend))
+        if (strcmp (textpos, "default"))
+          textpos = get (hlegend, "textposition");
+        endif
+        if (strcmp (position, "default"))
+          position = get (hlegend, "location");
+          inout = findstr (position, "outside");
+          if (! isempty (inout))
+            outside = true;
+            position = position(1:inout-1);
+          else
+            outside = false;
+          endif
+        endif
+        if (strcmp (orientation, "default"))
+          orientation = get (hlegend, "orientation");
+        endif
+        box = get (hlegend, "box");
+        fkids = get (fig, "children");
+
+        delete (hlegend);
+        hlegend = [];
+      else
+        if (strcmp (textpos, "default"))
+          textpos = "left";
+        endif
+        if (strcmp (position, "default"))
+          position = "northeast";
+        endif
+        if (strcmp (orientation, "default"))
+          orientation = "vertical";
+        endif
+        box = "off";
+      endif
+
+      ## Get axis size and fontsize in points.
+      ## Rely on listener to handle coversion.
+      units = get (ca(1), "units");
+      fontunits = get (ca(1), "fontunits");
+      unwind_protect
+        set (ca(1), "units", "points");
+        set (ca(1), "fontunits", "points");
+        ca_pos = get (ca(1), "position");
+        ca_outpos = get (ca(1), "outerposition");
+        ca_fontsize = get (ca(1), "fontsize");
+      unwind_protect_cleanup
+        set (ca(1), "units", units);
+        set (ca(1), "fontunits", fontunits);
+      end_unwind_protect
+
+      ## Padding between legend entries horizontally and vertically
+      xpad = 2;
+      ypad = 2;
+
+      ## Length of line segments in the legend in points
+      linelength = 15;
+
+      ## Create the axis first
+      ## FIXME hlegend should inherit properties from "ca"
+      curaxes = get (fig, "currentaxes");
+      unwind_protect
+        ud = ancestor(hplots, "axes");
+        if (!isscalar(ud))
+          ud = unique ([ud{:}]);
+        endif
+        if (isempty (hlegend))
+          addprops = true;
+          hlegend = axes ("tag", "legend", "userdata", struct ("handle", ud),
+                          "box", box,
+                          "xtick", [], "ytick", [], "xticklabel", "",
+                          "yticklabel", "", "zticklabel", "",
+                          "xlim", [0, 1], "ylim", [0, 1], "visible", "off",
+                          "activepositionproperty", "position");
+        else
+          addprops = false;
+          axes (hlegend);
+          delete (get (hlegend, "children"));
+        endif
+
+        ## Add text label to the axis first, checking their extents
+        nentries = numel (hplots);
+        texthandle = [];
+        maxwidth = 0;
+        maxheight = 0;
+        for k = 1 : nentries
+          if (strcmp (textpos, "right"))
+            texthandle = [texthandle, text(0, 0, text_strings {k},
+                                           "horizontalalignment", "left",
+                                           "userdata", hplots(k))];
+          else
+            texthandle = [texthandle, text(0, 0, text_strings {k},
+                                           "horizontalalignment", "right",
+                                           "userdata", hplots(k))];
+          endif
+          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));
+          unwind_protect_cleanup
+            set (texthandle (end), "units", units);
+          end_unwind_protect
+        endfor
+
+        num1 = nentries;
+        if (strcmp (orientation, "vertical"))
+          height = nentries * (ypad + maxheight);
+          if (outside)
+            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))
+              num1 = 0.9 * ca_pos(4) / (maxheight + ypad);
+            endif
+          endif
+        else
+          width = nentries * (ypad + maxwidth);
+          if (outside)
+            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))
+              num1 = 0.9 * ca_pos(3) / (maxwidth + ypad);
+            endif
+          endif
+        endif
+        num2 = ceil (nentries / num1);
+
+        xstep = 3 * xpad + (maxwidth + linelength);
+        if (strcmp (textpos, "right"))
+          xoffset = xpad;
+          txoffset = 2 * xpad + linelength;
+        else
+          xoffset = 2 * xpad + maxwidth;
+          txoffset = xpad + maxwidth;
+        endif
+        ystep = (ypad + maxheight);
+        yoffset = ystep / 2;
+
+        ## Place the legend in the desired position
+        if (strcmp (orientation, "vertical"))
+          lpos = [0, 0, num2 * xstep, num1 * ystep];
+        else
+          lpos = [0, 0, num1 * xstep, num2 * ystep];
+        endif
+        switch (position)
+          case "north"
+            if (outside)
+              lpos = [ca_pos(1) + (ca_pos(3) - lpos(3)) / 2, ...
+                      ca_outpos(2) + ca_outpos(4) - lpos(4) - ypad, lpos(3), ...
+                      lpos(4)];
+
+              new_pos = [ca_pos(1), ca_pos(2), ca_pos(3), ca_pos(4) - lpos(4)];
+            else
+              lpos = [ca_pos(1) + (ca_pos(3) - lpos(3)) / 2, ...
+                      ca_pos(2) + ca_pos(4) - lpos(4) - ypad, lpos(3), lpos(4)];
+            endif
+          case "south"
+            if (outside)
+              lpos = [ca_pos(1) + (ca_pos(3) - lpos(3)) / 2, ...
+                      ca_outpos(2) + ypad, lpos(3), lpos(4)];
+              new_pos = [ca_pos(1), ca_pos(2) + lpos(4), ca_pos(3), ...
+                         ca_pos(4) - lpos(4)];
+            else
+              lpos = [ca_pos(1) + (ca_pos(3) - lpos(3)) / 2, ...
+                      ca_pos(2) + ypad, lpos(3), lpos(4)];
+            endif
+          case "east"
+            if (outside)
+              lpos = [ca_outpos(1) + ca_outpos(3) - lpos(3) - ypad, ...
+                      ca_pos(2) + (ca_pos(4) - lpos(4)) / 2, lpos(3), lpos(4)];
+              new_pos = [ca_pos(1), ca_pos(2), ca_pos(3) - lpos(3), ca_pos(4)];
+            else
+              lpos = [ca_pos(1) + ca_pos(3) - lpos(3) - ypad, ...
+                      ca_pos(2) + (ca_pos(4) - lpos(4)) / 2, lpos(3), lpos(4)];
+            endif
+          case "west"
+            if (outside)
+              lpos = [ca_outpos(1) + ypad, ...
+                      ca_pos(2) + (ca_pos(4) - lpos(4)) / 2, ...
+                      lpos(3), lpos(4)];
+              new_pos = [ca_pos(1) + lpos(3), ca_pos(2), ...
+                         ca_pos(3) - lpos(3), ca_pos(4)];
+            else
+              lpos = [ca_pos(1) +  ypad, ...
+                      ca_pos(2) + (ca_pos(4) - lpos(4)) / 2, lpos(3), lpos(4)];
+            endif
+          case "northeast"
+            if (outside)
+              lpos = [ca_outpos(1) + ca_outpos(3) - lpos(3) - ypad, ...
+                      ca_pos(2) + ca_pos(4) - lpos(4), lpos(3), lpos(4)];
+              new_pos = [ca_pos(1), ca_pos(2), ca_pos(3) - lpos(3), ca_pos(4)];
+            else
+              lpos = [ca_pos(1) + ca_pos(3) - lpos(3) - ypad, ...
+                      ca_pos(2) + ca_pos(4) - lpos(4) - ypad, lpos(3), lpos(4)];
+            endif
+          case "northwest"
+            if (outside)
+              lpos = [ca_outpos(1) + ypad , ca_pos(2) + ca_pos(4) - lpos(4), ...
+                      lpos(3), lpos(4)];
+              new_pos = [ca_pos(1) + lpos(3), ca_pos(2), ...
+                         ca_pos(3) - lpos(3), ca_pos(4)];
+            else
+              lpos = [ca_pos(1) + ypad, ...
+                      ca_pos(2) + ca_pos(4) - lpos(4) - ypad, lpos(3), lpos(4)];
+            endif
+          case "southeast"
+            if (outside)
+              lpos = [ca_outpos(1) + ca_outpos(3) - lpos(3) - ypad, ...
+                      ca_pos(2), lpos(3), lpos(4)];
+              new_pos = [ca_pos(1), ca_pos(2), ...
+                         ca_pos(3) - lpos(3), ca_pos(4)];
+            else
+              lpos = [ca_pos(1) + ca_pos(3) - lpos(3) - ypad, ...
+                      ca_pos(2) + ypad, lpos(3), lpos(4)];
+            endif
+          case "southwest"
+            if (outside)
+              lpos = [ca_outpos(1) + ypad, ca_pos(2), lpos(3), lpos(4)];
+              new_pos = [ca_pos(1) + lpos(3), ca_pos(2), ...
+                         ca_pos(3) - lpos(3), ca_pos(4)];
+            else
+              lpos = [ca_pos(1) + ypad, ca_pos(2) + ypad, lpos(3), lpos(4)];
+            endif
+        endswitch
+
+        units = get (hlegend, "units");
+        unwind_protect
+          set (hlegend, "units", "points");
+          set (hlegend, "position", lpos);
+        unwind_protect_cleanup
+          set (hlegend, "units", units);
+        end_unwind_protect
+
+        ## Now write the line segments and place the text objects correctly
+        xk = 0;
+        yk = 0;
+        for k = 1 : numel (hplots)
+          hobjects = [hobjects, texthandle (k)];
+          switch (get (hplots(k), "type"))
+          case "line"
+            color = get (hplots(k), "color");
+            style = get (hplots(k), "linestyle");
+            if (! strcmp (style, "none"))
+              l1 = line ("xdata", ([xoffset, xoffset + linelength] + xk * xstep) / lpos(3),
+                         "ydata", [1, 1] .* (lpos(4) - yoffset - yk * ystep) / lpos(4),
+                         "color", color, "linestyle", style, "marker", "none",
+                         "userdata", hplots (k));
+              hobjects = [hobjects, l1];
+            endif
+            marker = get (hplots(k), "marker");
+            if (! strcmp (marker, "none"))
+              l1 = line ("xdata", (xoffset + 0.5 * linelength  + xk * xstep) / lpos(3),
+                         "ydata", (lpos(4) - yoffset - yk * ystep) / lpos(4),
+                         "color", color, "linestyle", "none", "marker", marker,
+                         "markeredgecolor", get (hplots (k), "markeredgecolor"),
+                         "markerfacecolor", get (hplots (k), "markerfacecolor"),
+                         "markersize", get (hplots (k), "markersize"),
+                         "userdata", hplots (k));
+              hobjects = [hobjects, l1];
+            endif
+
+            addlistener(hplots(k), "color", {@updateline, hlegend, linelength});
+            addlistener(hplots(k), "linestyle", {@updateline, hlegend, linelength});
+            addlistener(hplots(k), "marker", {@updateline, hlegend, linelength});
+            addlistener(hplots(k), "markeredgecolor", {@updateline, hlegend, linelength});
+            addlistener(hplots(k), "markerfacecolor", {@updateline, hlegend, linelength});
+            addlistener(hplots(k), "markersize", {@updateline, hlegend, linelength});
+            addlistener(hplots(k), "displayname", {@updateline, hlegend, linelength});
+          case "patch"
+          case "surface"
+          endswitch
+          set (texthandle (k), "position", [(txoffset + xk * xstep) / lpos(3), ...
+                                            (lpos(4) - yoffset - yk * ystep) / lpos(4)]);
+          if (strcmp (orientation, "vertical"))
+            yk++;
+            if (yk > num1)
+              yk = 0;
+              xk++;
+            endif
+          else
+            xk++;
+            if (xk > num1)
+              xk = 0;
+              yk++;
+            endif
+          endif
+        endfor
+
+        ## Add an invisible text object to original axis
+        ## that when it is destroyed will remove the legend
+        t1 = text (0, 0, "", "parent", ca(1), "tag", "legend",
+                   "handlevisibility", "off", "visible", "off",
+                   "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 axis to original size if the legend is deleted,
+        ## 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);
+            unwind_protect_cleanup
+              set (ca(i), "units", units);
+            end_unwind_protect
+          endfor
+
+          set (hlegend, "deletefcn", {@deletelegend2, ca, ...
+                                      ca_pos, ca_outpos, t1, hplots});
+          addlistener (hlegend, "visible", {@hideshowlegend, ca, ...
+                                            ca_pos, new_pos});
+        else
+          set (hlegend, "deletefcn", {@deletelegend2, ca, [], [], t1, hplots});
+        endif
+
+        if (addprops)
+          addproperty ("edgecolor", hlegend, "color", [0, 0, 0]);
+          addproperty ("textcolor", hlegend, "color", [0, 0, 0]);
+          addproperty ("location", hlegend, "radio", "north|south|east|west|{northeast}|southeast|northwest|southwest|northoutside|southoutside|eastoutside|westoutside|northeastoutside|southeastoutside|northwestoutside|southwestoutside");
+          addproperty ("orientation", hlegend, "radio",
+                       "{vertical}|horizontal");
+          addproperty ("string", hlegend, "any", text_strings);
+          addproperty ("textposition", hlegend, "radio", "{left}|right");
+        else
+          set (hlegend, "string", text_strings);
+        endif
+
+        if (outside)
+          set (hlegend, "location", strcat (position, "outside"),
+               "orientation", orientation, "textposition", textpos);
+        else
+          set (hlegend, "location", position, "orientation", orientation,
+               "textposition", textpos);
+        endif
+        if (addprops)
+          addlistener (hlegend, "edgecolor", @updatelegendtext);
+          addlistener (hlegend, "textcolor", @updatelegendtext);
+          addlistener (hlegend, "interpreter", @updatelegendtext);
+          addlistener (hlegend, "location", @updatelegend);
+          addlistener (hlegend, "orientation", @updatelegend);
+          addlistener (hlegend, "string", @updatelegend);
+          addlistener (hlegend, "textposition", @updatelegend);
+        endif
+      unwind_protect_cleanup
+        set (fig, "currentaxes", curaxes);
+      end_unwind_protect
+    endif
+  endif
+
+  if (nargout > 0)
+    hlegend2 = hlegend;
+    hobjects2 = hobjects;
+    hplot2 = hplots;
+    text_strings2 = text_strings;
+  endif
+
+endfunction
+
+function updatelegend (h, d)
+  persistent recursive = false;
+  if (! recursive)
+    recursive = true;
+    unwind_protect
+      hax = getfield (get (h, "userdata"), "handle");
+      [hplots, text_strings] = __getlegenddata__ (h);
+      h = legend (hax, hplots, get (h, "string"));
+    unwind_protect_cleanup
+      recursive = false;
+    end_unwind_protect
+  endif
+endfunction
+
+function updatelegendtext (h, d)
+  hax = get (h, "userdata").handle;
+  kids = get (h, "children");
+  text_kids = findobj (kids, "-property", "interpreter", "type", "text");
+  interpreter = get (h, "interpreter");
+  textcolor = get (h, "textcolor");
+  set (kids, "interpreter", interpreter, "color", textcolor);
+  hobj = cell2mat (get (kids, "userdata"));
+  set (hobj, "interpreter", interpreter);
+endfunction
+
+function hideshowlegend (h, d, ca, pos1, pos2)
+  isvisible = strcmp (get (h, "visible"), "off");
+  if (! isvisible)
+    kids = get (h, "children");
+    for i = 1 : numel (kids)
+      if (! strcmp (get (kids(i), "visible"), "off"))
+        isvisible = true;
+        break;
+      endif
+    endfor
+  endif
+
+  for i = 1 : numel (ca)
+    if (ishandle (ca(i)) && strcmp (get (ca(i), "type"), "axes")
+        && (isempty (gcbf()) || strcmp (get (gcbf(), "beingdeleted"),"off"))
+        && strcmp (get (ca(i), "beingdeleted"), "off"))
+      units = get (ca(i), "units");
+      unwind_protect
+        set (ca(i), "units", "points");
+        if (isvisible)
+          set (ca(i), "position", pos2);
+        else
+          set (ca(i), "position", pos1);
+        endif
+      unwind_protect_cleanup
+        set (ca(i), "units", units);
+      end_unwind_protect
+    endif
+  endfor
+endfunction
+
+function deletelegend1 (h, d, ca)
+  if (ishandle (ca) && strcmp (get (ca, "type"), "axes")
+      && (isempty (gcbf()) || strcmp (get (gcbf(), "beingdeleted"),"off"))
+      && strcmp (get (ca, "beingdeleted"), "off"))
+    delete (ca);
+  endif
+endfunction
+
+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"))
+        && strcmp (get (ca(i), "beingdeleted"), "off"))
+      if (!isempty (pos) && !isempty(outpos))
+        units = get (ca(i), "units");
+        unwind_protect
+          set (ca(i), "units", "points");
+          set (ca(i), "position", pos, "deletefcn", "");
+        unwind_protect_cleanup
+          set (ca(i), "units", units);
+        end_unwind_protect
+      endif
+    endif
+  endfor
+  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");
+    endif
+  endfor
+endfunction
+
+function updateline (h, d, hlegend, linelength)
+  lm = [];
+  ll = [];
+  kids = get (hlegend, "children");
+  for i = 1 : numel (kids)
+    if (get (kids (i), "userdata") == h
+        && strcmp (get (kids(i), "type"), "line"))
+      if (strcmp (get (kids (i), "marker"), "none"))
+        ll = kids (i);
+      else
+        lm = kids (i);
+      endif
+    endif
+  endfor
+
+  linestyle = get (h, "linestyle");
+  marker = get (h, "marker");
+  displayname = get (h, "displayname");
+
+  if ((isempty (displayname)
+       || (strcmp (marker, "none") && strcmp (linestyle, "none")))
+       && (! isempty (lm) || isempty (ll)))
+    ## An element was removed from the legend. Need to recall the
+    ## legend function to recreate a new legend
+    [hplots, text_strings] = __getlegenddata__ (hlegend);
+    for i = 1 : numel (hplots)
+      if (hplots (i) == h)
+        hplots(i) = [];
+        text_strings(i) = [];
+        break;
+      endif
+    endfor
+    legend (hplots, text_strings);
+  elseif ((!isempty (displayname)
+           && (! strcmp (marker, "none") || ! strcmp (linestyle, "none")))
+          && isempty (lm) && isempty (ll))
+    ## An element was added to the legend. Need to recall the
+    ## legend function to recreate a new legend
+    [hplots, text_strings] = __getlegenddata__ (hlegend);
+    hplots = [hplots, h];
+    text_strings = {text_strings{:}, displayname};
+    legend (hplots, text_strings);
+  else
+    if (! isempty (ll))
+      ypos1 = get (ll,"ydata");
+      xpos1 = get (ll,"xdata");
+      ypos2 = ypos1(1);
+      xpos2 = sum(xpos1) / 2;
+      delete (ll);
+      if (! isempty (lm))
+        delete (lm);
+      endif
+    else
+      ypos2 = get (lm,"ydata");
+      xpos2 = get (lm,"xdata");
+      ypos1 = [ypos2, ypos2];
+      xpos1 = xpos2 + [-0.5, 0.5] * linelength;
+      delete (lm);
+    endif
+    if (! strcmp (linestyle, "none"))
+      line ("xdata", xpos1, "ydata", ypos1, "color", get (h, "color"),
+            "linestyle", get (h, "linestyle"), "marker", "none",
+            "userdata", h, "parent", hlegend);
+    endif
+    if (! strcmp (marker, "none"))
+      line ("xdata", xpos2, "ydata", ypos2, "color", get (h, "color"),
+            "marker", marker, "markeredgecolor", get (h, "markeredgecolor"),
+            "markerfacecolor", get (h, "markerfacecolor"),
+            "markersize", get (h, "markersize"), "linestyle", "none",
+            "userdata", h, "parent", hlegend);
+    endif
+  endif
+endfunction
+
+%!demo
+%! clf
+%! x = 0:1;
+%! plot (x, x, ";I am Blue;", x, 2*x, ";I am Green;", x, 3*x, ";I am Red;")
+
+%!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 mising")
+
+%!demo
+%! clf
+%! plot(1:10, 1:10, 1:10, fliplr(1:10));
+%! title("incline is blue and decline is green");
+%! legend({"I am blue", "I am green"}, "location", "east");
+%! legend({"I am blue", "I am green"}, "location", "east");
+%! legend hide
+%! legend show
+
+%!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
+%! plot(1:10, 1:10, 1:10, fliplr(1:10));
+%! title("Legend with box on")
+%! legend({"I am blue", "I am green"}, "location", "east");
+%! legend boxon
+
+%!demo
+%! clf
+%! plot(1:10, 1:10, 1:10, fliplr(1:10));
+%! title("Legend with text to the right")
+%! legend({"I am blue", "I am green"}, "location", "east");
+%! legend right
+
+%!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");
+
+%!demo
+%! clf
+%! labels = {};
+%! colororder = get (gca, "colororder");
+%! for i = 1:5
+%!   h = plot(1:100, i + rand(100,1)); hold on;
+%!   set (h, "color", colororder(i,:))
+%!   labels = {labels{:}, cstrcat("Signal ", num2str(i))};
+%! endfor
+%! hold off;
+%! title("Signals with random offset and uniform noise")
+%! xlabel("Sample Nr [k]"); ylabel("Amplitude [V]");
+%! legend(labels, "location", "southoutside");
+%! legend("boxon");
+
+%!demo
+%! clf
+%! labels = {};
+%! colororder = get (gca, "colororder");
+%! for i = 1:5
+%!   h = plot(1:100, i + rand(100,1)); hold on;
+%!   set (h, "color", colororder(i,:))
+%!   labels = {labels{:}, cstrcat("Signal ", num2str(i))};
+%! endfor
+%! hold off;
+%! title("Signals with random offset and uniform noise")
+%! xlabel("Sample Nr [k]"); ylabel("Amplitude [V]");
+%! legend(labels{:}, "location", "southoutside")
+%! legend("boxon")
+
+%!demo
+%! clf
+%! x = linspace (0, 10);
+%! plot (x, x);
+%! hold ("on");
+%! stem (x, x.^2, 'g')
+%! legend ("linear");
+%! hold ("off");
+
+%!demo
+%! clf
+%! x = linspace (0, 10);
+%! plot (x, x, x, x.^2);
+%! legend ("linear");
+
+%!demo
+%! clf
+%! x = linspace (0, 10);
+%! plot (x, x, x, x.^2);
+%! legend ("linear", "quadratic");
+
+%!demo
+%! clf
+%! rand_2x3_data1 = [0.341447, 0.171220, 0.284370; 0.039773, 0.731725, 0.779382];
+%! bar (rand_2x3_data1);
+%! ylim ([0 1.0]);
+%! legend ({"1st Bar", "2nd Bar", "3rd Bar"});
+
+%!demo
+%! clf
+%! rand_2x3_data2 = [0.44804, 0.84368, 0.23012; 0.72311, 0.58335, 0.90531];
+%! bar (rand_2x3_data2);
+%! ylim ([0 1.2]);
+%! legend ("1st Bar", "2nd Bar", "3rd Bar");
+%! legend right
+
+%!demo
+%! clf
+%! x = 0:0.1:7;
+%! h = plot (x, sin(x), x, cos(x), x, sin(x.^2/10), x, cos(x.^2/10));
+%! title ("Only the sin() objects have keylabels");
+%! legend (h([1, 3]), {"sin(x)", "sin(x^2/10)"}, "location", "southwest");
+
+%!demo
+%! clf
+%! x = 0:0.1:10;
+%! plot (x, sin(x), ";sin(x);")
+%! hold all
+%! plot (x, cos(x), ";cos(x);")
+%! hold off
+
+%!demo
+%! clf
+%! x = 0:0.1:10;
+%! plot (x, sin(x), ";sin(x);")
+%! hold all
+%! plot (x, cos(x), ";cos(x);")
+%! hold off
+%! legend ({"sin(x)", "cos(x)"}, "location", "northeastoutside")
+
+%!demo
+%! clf
+%! x = 0:10;
+%! plot (x, rand (11));
+%! xlabel ("Indices")
+%! ylabel ("Random Values")
+%! title ("Legend ""off"" should delete the legend")
+%! legend (cellstr (num2str ((1:10)')), "location", "northeastoutside")
+%! legend off
+%! axis ([0, 10, 0 1])
+
+%!demo
+%! clf
+%! x = 1:5;
+%! subplot (2, 2, 1)
+%! plot (x, rand (numel (x)));
+%! legend (cellstr (num2str (x')), "location", "northwestoutside")
+%! legend boxon
+%! subplot (2, 2, 2)
+%! plot (x, rand (numel (x)));
+%! legend (cellstr (num2str (x')), "location", "northeastoutside")
+%! legend boxon
+%! subplot (2, 2, 3);
+%! plot (x, rand (numel (x)));
+%! legend (cellstr (num2str (x')), "location", "southwestoutside")
+%! legend boxon
+%! subplot (2, 2, 4)
+%! plot (x, rand (numel (x)));
+%! legend (cellstr (num2str (x')), "location", "southeastoutside")
+%! legend boxon
+
+%!demo
+%! clf
+%! plot (rand (2))
+%! title ("Warn of extra labels")
+%! 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")
+