########################################################################
##
## Copyright (C) 1994-2026 The Octave Project Developers
##
## See the file COPYRIGHT.md in the top-level directory of this
## distribution or <https://octave.org/copyright/>.
##
## 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
## <https://www.gnu.org/licenses/>.
##
########################################################################

## -*- texinfo -*-
## @deftypefn  {} {} axis ()
## @deftypefnx {} {} axis ([@var{x_lo} @var{x_hi}])
## @deftypefnx {} {} axis ([@var{x_lo} @var{x_hi} @var{y_lo} @var{y_hi}])
## @deftypefnx {} {} axis ([@var{x_lo} @var{x_hi} @var{y_lo} @var{y_hi} @var{z_lo} @var{z_hi}])
## @deftypefnx {} {} axis ([@var{x_lo} @var{x_hi} @var{y_lo} @var{y_hi} @var{z_lo} @var{z_hi} @var{c_lo} @var{c_hi}])
## @deftypefnx {} {} axis (@var{option})
## @deftypefnx {} {} axis (@var{option1}, @var{option2}, @dots{})
## @deftypefnx {} {} axis (@var{hax}, @dots{})
## @deftypefnx {} {@var{limits} =} axis ()
## Set axis limits and appearance.
##
## The argument @var{limits} should be a 2-, 4-, 6-, or 8-element vector.  The
## first and second elements specify the lower and upper limits for the
## x-axis.  The third and fourth specify the limits for the y-axis, the fifth
## and sixth specify the limits for the z-axis, and the seventh and eighth
## specify the limits for the color axis.  The special values @code{-Inf} and
## @code{Inf} may be used to indicate that the limit should be automatically
## computed based on the data in the axes.
##
## Without any arguments, @code{axis} turns autoscaling on.
##
## With one output argument, @code{@var{limits} = axis} returns the current
## axis limits.
##
## The vector argument specifying limits is optional, and additional string
## arguments may be used to specify various axis properties.
##
## The following options control the aspect ratio of the axes.
##
## @table @asis
## @item @qcode{"equal"}
## Force x-axis unit distance to equal y-axis (and z-axis) unit distance.
##
## @item @qcode{"square"}
## Force a square axis aspect ratio.
##
## @item @nospell{@qcode{"vis3d"}}
## Set aspect ratio modes (@qcode{"DataAspectRatio"},
## @qcode{"PlotBoxAspectRatio"}) to @qcode{"manual"} for rotation without
## stretching.
##
## @item  @qcode{"normal"}
## @itemx @qcode{"fill"}
## Restore default automatically computed aspect ratios.
## @end table
##
## @noindent
## The following options control the way axis limits are interpreted.
##
## @table @asis
## @item  @qcode{"auto"}
## @itemx @qcode{"auto[xyz]"}
## @itemx @qcode{"auto [xyz]"}
## Set nice auto-computed limits around the data for all axes, or only
## the specified axes.
##
## @item @qcode{"manual"}
## Fix the current axes limits.
##
## @item @qcode{"tickaligned"}
## Fix axes to the limits of the closest ticks.
##
## @item @qcode{"tight"}
## Fix axes to the limits of the data.
##
## @item @qcode{"padded"}
## Fix axes to the limits of the data plus margins of about 7% of the
## data extent.
##
## @item @qcode{"image"}
## Equivalent to @qcode{"tight"} and @qcode{"equal"}.
##
## @end table
##
## @noindent
## The following options affect the appearance of tick marks.
##
## @table @asis
## @item  @qcode{"tic"}
## @itemx @qcode{"tic[xyz]"}
## @itemx @qcode{"tic [xyz]"}
## Turn tick marks on for all axes, or turn them on for the specified axes and
## off for the remainder.
##
## @item  @qcode{"label"}
## @itemx @qcode{"label[xyz]"}
## @itemx @qcode{"label [xyz]"}
## Turn tick labels on for all axes, or turn them on for the specified axes
## and off for the remainder.
##
## @item @qcode{"nolabel"}
## Turn tick labels off for all axes.
## @end table
##
## @noindent
## The following options affect the direction of increasing values on the axes.
##
## @table @asis
## @item @qcode{"xy"}
## Default y-axis, larger values are near the top.
##
## @item @qcode{"ij"}
## Reverse y-axis, smaller values are near the top.
## @end table
##
## @noindent
## The following options affects the visibility of the axes.
##
## @table @asis
## @item @qcode{"on"}
## Make the axes visible.
##
## @item @qcode{"off"}
## Hide the axes.
## @end table
##
## If the first argument @var{hax} is an axes handle, then operate on this
## axes rather than the current axes returned by @code{gca}.
##
## Example 1: set X/Y limits and force a square aspect ratio
##
## @example
## axis ([1, 2, 3, 4], "square");
## @end example
##
## Example 2: enable tick marks on all axes,
##            enable tick mark labels only on the y-axis
##
## @example
## axis ("tic", "labely");
## @end example
##
## @seealso{xlim, ylim, zlim, clim, daspect, pbaspect, box, grid}
## @end deftypefn

function limits = axis (varargin)

  [hax, varargin, nargin] = __plt_get_axis_arg__ ("axis", varargin{:});

  oldfig = [];
  if (! isempty (hax))
    oldfig = get (0, "currentfigure");
  endif
  unwind_protect
    if (isempty (hax))
      hax = gca ();
    endif
    if (nargin == 0)
      limits = __axis__ (hax, varargin{:});
    else
      __axis__ (hax, varargin{:});
    endif
  unwind_protect_cleanup
    if (! isempty (oldfig))
      set (0, "currentfigure", oldfig);
    endif
  end_unwind_protect

endfunction

function limits = __axis__ (ca, varargin)

  if (nargin == 1)
    if (nargout == 0)
      set (ca, "xlimmode", "auto", "ylimmode", "auto", "zlimmode", "auto");
    else
      xlim = get (ca, "xlim");
      ylim = get (ca, "ylim");
      view = get (ca, "view");
      if (view(2) == 90)
        limits = [xlim, ylim];
      else
        zlim = get (ca, "zlim");
        limits = [xlim, ylim, zlim];
      endif
    endif
    return;
  endif

  for arg = varargin
    opt = arg{1};

    if (ischar (opt))
      len = length (opt);

      ## 'matrix mode' to reverse the y-axis
      if (strcmpi (opt, "ij"))
        set (ca, "ydir", "reverse");
      elseif (strcmpi (opt, "xy"))
        set (ca, "ydir", "normal");

      ## aspect ratio
      elseif (strcmpi (opt, "image"))
        __axis__ (ca, "equal");
        set (ca, "plotboxaspectratiomode", "auto", ...
                 "xlimmode", "auto", "ylimmode", "auto", ...
                 "zlimmode", "auto", ...
                 "xlimitmethod", "tight", "ylimitmethod", "tight");
      elseif (strcmpi (opt, "square"))
        set (ca, "dataaspectratiomode", "auto",
                 "plotboxaspectratio", [1, 1, 1]);
      elseif (strcmp (opt, "equal"))
        is2dview = (get (ca, "view")(2) == 90);
        if (is2dview)
          ## Save & later restore axes aspect ratio
          ca_units = get (ca, "units");
          set (ca, "units", "pixels");
          axis_pos = get (ca, "position");
          set (ca, "units", ca_units);
          pbratio = [axis_pos(3), axis_pos(4), axis_pos(4)];
        endif

        daratio = get (ca, "dataaspectratio");
        if (all (daratio != [1, 1, 1]))
          set (ca, "dataaspectratio", [1, 1, 1]);
        else
          set (ca, "dataaspectratio", [1+eps, 1, 1],
                   "dataaspectratio", [1, 1, 1]);
        endif

        ## Matlab only adjusts plotboxaspectratio for 2-D figures, but
        ## Octave needs to do it for 3-D as well.
        if (is2dview)
          set (ca, "plotboxaspectratio", pbratio);
        else
          pbratio = get (ca, "plotboxaspectratio");
          if (all (pbratio != [1, 1, 1]))
            set (ca, "plotboxaspectratio", [1, 1, 1]);
          else
            set (ca, "plotboxaspectratio", [1+eps, 1, 1],
                     "plotboxaspectratio", [1, 1, 1]);
          endif
        endif
      elseif (strcmpi (opt, "vis3d"))
        ## Fix aspect ratio modes for rotation without stretching.
        set (ca, "dataaspectratiomode", "manual",
                 "plotboxaspectratiomode", "manual");
      elseif (strcmpi (opt, "normal") || strcmpi (opt, "fill"))
        ## Set plotboxaspectratio to something obtuse so that switching
        ## back to "auto" will force a re-calculation.
        set (ca, "plotboxaspectratio", [3 2 1]);
        set (ca, "plotboxaspectratiomode", "auto",
                 "dataaspectratiomode", "auto");

      ## axis limits
      elseif (strncmpi (opt, "auto", 4))
        if (len == 4)
          set (ca, "xlimmode", "auto", "ylimmode", "auto", "zlimmode", "auto");
        else
          if (any (opt == "x"))
            set (ca, "xlimmode", "auto");
          endif
          if (any (opt == "y"))
            set (ca, "ylimmode", "auto");
          endif
          if (any (opt == "z"))
            set (ca, "zlimmode", "auto");
          endif
        endif
      elseif (strcmpi (opt, "manual"))
        ## fixes the axis limits
        set (ca, "xlimmode", "manual", "ylimmode", "manual",
                 "zlimmode", "manual");
      elseif (strcmpi (opt, "tickaligned"))
        ## sets the axis limits to closest ticks.
        set (ca, "xlimmode", "auto", "ylimmode", "auto", ...
                 "zlimmode", "auto", ...
                 "xlimitmethod", "tickaligned", ...
                 "ylimitmethod", "tickaligned", ...
                 "zlimitmethod", "tickaligned");
      elseif (strcmpi (opt, "tight"))
        ## sets the axis limits to the min and max of all data.
        set (ca, "xlimmode", "auto", "ylimmode", "auto", ...
                 "zlimmode", "auto", ...
                 "xlimitmethod", "tight", "ylimitmethod", "tight",
                 "zlimitmethod", "tight");
      elseif (strcmpi (opt, "padded"))
        ## sets the axis limits to the min and max of all data plus padding.
        set (ca, "xlimmode", "auto", "ylimmode", "auto", ...
                 "zlimmode", "auto", ...
                 "xlimitmethod", "padded", ...
                 "ylimitmethod", "padded", ...
                 "zlimitmethod", "padded");
      ## visibility
      elseif (strcmpi (opt, "on"))
        set (ca, "visible", "on");
      elseif (strcmpi (opt, "off"))
        set (ca, "visible", "off");

      ## tick marks
      elseif (strcmpi (opt, "tic"))
        set (ca, "xtickmode", "auto", "ytickmode", "auto", "ztickmode", "auto",
                 "visible", "on");
      elseif (strncmpi (opt, "tic", 3))
        if (any (opt == "x"))
          set (ca, "xtickmode", "auto");
        else
          set (ca, "xtick", []);
        endif
        if (any (opt == "y"))
          set (ca, "ytickmode", "auto");
        else
          set (ca, "ytick", []);
        endif
        if (any (opt == "z"))
          set (ca, "ztickmode", "auto");
        else
          set (ca, "ztick", []);
        endif

      ## labels
      elseif (strcmpi (opt, "label"))
        set (ca, "xticklabelmode", "auto", "yticklabelmode", "auto",
                 "zticklabelmode", "auto");
      elseif (strcmpi (opt, "nolabel"))
        set (ca, "xticklabel", {}, "yticklabel", {}, "zticklabel", {})
      elseif (strncmpi (opt, "label", 5))
        if (any (opt == "x"))
          set (ca, "xticklabelmode", "auto");
        else
          set (ca, "xticklabel", "");
        endif
        if (any (opt == "y"))
          set (ca, "yticklabelmode", "auto");
        else
          set (ca, "yticklabel", "");
        endif
        if (any (opt == "z"))
          set (ca, "zticklabelmode", "auto");
        else
          set (ca, "zticklabel", "");
        endif

      else
        warning ("axis: unknown option '%s'", opt);
      endif

    elseif (isnumeric (opt) && isvector (opt))

      nel = numel (opt);

      if (nel != 2 && nel != 4 && nel != 6 && nel != 8)
        error ("axis: LIMITS vector must have 2, 4, 6, or 8 elements");
      endif

      for i = 1:2:nel
        if (opt(i) >= opt(i+1))
          error ("axis: LIMITS(%d) must be less than LIMITS(%d)", i, i+1);
        endif
      endfor

      if (nel > 1)
        xlim (ca, opt(1:2));
      endif

      if (nel > 3)
        ylim (ca, opt(3:4));
      endif

      if (nel > 5)
        zlim (ca, opt(5:6));
      endif

      if (nel > 7)
        clim (ca, opt(7:8));
      endif

    else
      error ("axis: expecting no args, or a numeric vector with 2, 4, 6, or 8 elements");
    endif

  endfor

endfunction


%!demo
%! clf;
%! t = 0:0.01:2*pi;
%! x = sin (t);
%!
%! subplot (221);
%!  plot (t, x);
%!  title ("normal plot");
%!
%! subplot (222);
%!  plot (t, x);
%!  title ("axis square");
%!  axis ("square");
%!
%! subplot (223);
%!  plot (t, x);
%!  title ("axis equal");
%!  axis ("equal");
%!
%! subplot (224);
%!  plot (t, x);
%!  title ("normal plot again");
%!  axis ("normal");

%!demo
%! clf;
%! t = 0:0.01:2*pi;
%! x = sin (t);
%!
%! subplot (121);
%!  plot (t, x);
%!  title ({"axis ij", "Y-axis reversed"});
%!  axis ("ij");
%!  legend ("sine");
%!
%! subplot (122);
%!  plot (t, x);
%!  title ("axis xy");
%!  title ({"axis ij", "Y-axis normal"});
%!  axis ("xy");
%!  legend ("sine");

%!demo
%! clf;
%! def_ticklen = get (0, "DefaultAxesTickLength");
%! set (0, "DefaultAxesTickLength", [.028, .025]);
%! t = 0:0.01:2*pi;
%! x = sin (t);
%!
%! subplot (331);
%!  plot (t, x);
%!  title ("x ticks and labels");
%!  axis ("ticx");
%!
%! subplot (332);
%!  plot (t, x);
%!  title ("y ticks and labels");
%!  axis ("ticy");
%!
%! subplot (333);
%!  plot (t, x);
%!  title ("axis off");
%!  axis ("off");
%!
%! subplot (334);
%!  plot (t, x);
%!  title ("x and y ticks, x labels");
%!  axis ("labelx","tic");
%!
%! subplot (335);
%!  plot (t, x);
%!  title ("x and y ticks, y labels");
%!  axis ("labely","tic");
%!
%! subplot (336);
%!  plot (t, x);
%!  title ("all ticks but no labels");
%!  axis ("nolabel","tic");
%!
%! subplot (337);
%!  plot (t, x);
%!  title ("x ticks, no labels");
%!  axis ("nolabel","ticx");
%!
%! subplot (338);
%!  plot (t, x);
%!  title ("y ticks, no labels");
%!  axis ("nolabel","ticy");
%!
%! subplot (339);
%!  plot (t, x);
%!  title ("all ticks and labels");
%!  axis ("on");
%!
%! set (0, "DefaultAxesTickLength", def_ticklen);

%!demo
%! clf;
%! t = 0:0.01:2*pi;
%! x = sin (t);
%!
%! subplot (321);
%!  plot (t, x);
%!  title ("axes at [0 3 0 1]");
%!  axis ([0,3,0,1]);
%!
%! subplot (322);
%!  plot (t, x);
%!  title ("auto");
%!  axis ("auto");
%!
%! subplot (323);
%!  plot (t, x, ";sine [0:2pi];"); hold on;
%!  plot (-3:3,-3:3, ";line (-3,-3)->(3,3);"); hold off;
%!  title ("manual");
%!  axis ("manual");
%!
%! subplot (324);
%!  plot (t, x, ";sine [0:2pi];");
%!  title ("axes at [0 3 0 1], then autox");
%!  axis ([0,3,0,1]);
%!  axis ("autox");
%!
%! subplot (325);
%!  plot (t, x, ";sine [0:2pi];");
%!  title ("axes at [3 6 0 1], then autoy");
%!  axis ([3,6,0,1]);
%!  axis ("autoy");
%!
%! subplot (326);
%!  plot (t, sin (t), t, -2*sin (t/2));
%!  axis ("tight");
%!  title ("tight");

%!demo
%! clf;
%! x = 0:0.1:10;
%! plot (x, sin (x));
%! axis image;
%! title ({"image", 'equivalent to "tight" & "equal"'});

%!demo
%! clf;
%! colormap ("default");
%! [x,y,z] = peaks (50);
%! x1 = max (x(:));
%! pcolor (x-x1, y-x1/2, z);
%! hold on;
%! [x,y,z] = sombrero ();
%! s = x1 / max (x(:));
%! pcolor (s*x+x1, s*y+x1/2, 5*z);
%! axis tight;
%! title ('"tight" when two axes objects exist');

%!demo
%! clf;
%! loglog (1:20, "-s");
%! axis tight;
%! title ('"tight" on loglog plot');

%!demo
%! clf;
%! x = y = 0.5:0.5:12;
%! subplot (3,1,1);
%! plot (x, y, "-s");
%! axis tickaligned
%! title ("tickaligned");
%! subplot (3,1,2);
%! plot (x, y, "-s");
%! axis padded
%! title ("padded");
%! subplot (3,1,3);
%! plot (x, y, "-s");
%! axis tight
%! title ("tight");

%!demo
%! clf;
%! x = y = 0.5:0.5:12;
%! subplot (3,1,1);
%! loglog (x, y, "-s");
%! axis tickaligned
%! title ("tickaligned");
%! subplot (3,1,2);
%! loglog (x, y, "-s");
%! axis padded
%! title ("padded");
%! subplot (3,1,3);
%! loglog (x, y, "-s");
%! axis tight
%! title ("tight");

%!test
%! hf = figure ("visible", "off");
%! unwind_protect
%!   plot (11:20, [21:24, NaN, -Inf, 27:30]);
%!   hold on;
%!   plot (11:20, 25.5 + rand (10));
%!   axis tight;
%!   assert (axis (), [11 20 21 30]);
%! unwind_protect_cleanup
%!   close (hf);
%! end_unwind_protect

%!test
%! hf = figure ("visible", "off");
%! unwind_protect
%!   a = logspace (-5, 1, 10);
%!   loglog (a, -a);
%!   axis tight;
%!   ## Compare to powers of 10 rather than exponential literals because of an
%!   ## upstream bug in mingw-w64: https://sourceforge.net/p/mingw-w64/bugs/466/
%!   assert (axis (), [10^-5, 10, -10, -10^-5]);
%! unwind_protect_cleanup
%!   close (hf);
%! end_unwind_protect

## Test 'axis tight' with differently oriented, differently numbered data vecs
%!test <*40036>
%! hf = figure ("visible", "off");
%! unwind_protect
%!   Z = peaks (linspace (-3, 3, 49), linspace (-2, 2, 29));
%!   surf (Z);
%!   axis tight;
%!   assert (axis (), [1 49 1 29 min(Z(:)) max(Z(:))]);
%! unwind_protect_cleanup
%!   close (hf);
%! end_unwind_protect

## Test 'axis tight' remains after addition of new data
%!test
%! hf = figure ("visible", "off");
%! unwind_protect
%!   plot (1:10)
%!   axis tight;
%!   assert (axis (), [1 10 1 10]);
%!   hold on;
%!   plot (1:11)
%!   assert (axis (), [1 11 1 11]);
%! unwind_protect_cleanup
%!   close (hf);
%! end_unwind_protect

## Even on errors, axis can display a figure.
%!error <LIMITS vector must have .* elements>
%! hf = figure ("visible", "off");
%! unwind_protect
%!   axis (1:5)
%! unwind_protect_cleanup
%!   close (hf);
%! end_unwind_protect

%!error <LIMITS\(3\) must be less than LIMITS\(4\)>
%! hf = figure ("visible", "off");
%! unwind_protect
%!   axis ([1 2 4 3])
%! unwind_protect_cleanup
%!   close (hf);
%! end_unwind_protect

%!error <expecting no args, or a numeric vector with .* elements>
%! hf = figure ("visible", "off");
%! unwind_protect
%!   axis ({1,2})
%! unwind_protect_cleanup
%!   close (hf);
%! end_unwind_protect
