view scripts/image/rgbplot.m @ 30564:796f54d4ddbf stable

update Octave Project Developers copyright for the new year In files that have the "Octave Project Developers" copyright notice, update for 2021. In all .txi and .texi files except gpl.txi and gpl.texi in the doc/liboctave and doc/interpreter directories, change the copyright to "Octave Project Developers", the same as used for other source files. Update copyright notices for 2022 (not done since 2019). For gpl.txi and gpl.texi, change the copyright notice to be "Free Software Foundation, Inc." and leave the date at 2007 only because this file only contains the text of the GPL, not anything created by the Octave Project Developers. Add Paul Thomas to contributors.in.
author John W. Eaton <jwe@octave.org>
date Tue, 28 Dec 2021 18:22:40 -0500
parents 7854d5752dd2
children 597f3ee61a48
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########################################################################
##
## Copyright (C) 2012-2022 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  {} {} rgbplot (@var{cmap})
## @deftypefnx {} {} rgbplot (@var{cmap}, @var{style})
## @deftypefnx {} {@var{h} =} rgbplot (@dots{})
## Plot the components of a colormap.
##
## Two different @var{style}s are available for displaying the @var{cmap}:
##
## @table @asis
## @item profile (default)
## Plot the RGB line profile of the colormap for each of the channels (red,
## green and blue) with the plot lines colored appropriately.  Each line
## represents the intensity of an RGB component across the colormap.
##
## @item composite
## Draw the colormap across the X-axis so that the actual index colors are
## visible rather than the individual color components.
##
## @end table
##
## The optional return value @var{h} is a graphics handle to the created plot.
##
## Run @code{demo rgbplot} to see an example of @code{rgbplot} and each style
## option.
## @seealso{colormap}
## @end deftypefn

function h = rgbplot (cmap, style = "profile")

  if (nargin < 1)
    print_usage ();
  endif

  if (! iscolormap (cmap))
    error ("rgbplot: CMAP must be a valid colormap");
  elseif (! ischar (style))
    error ("rgbplot: STYLE must be a string");
  endif

  switch (tolower (style))
    case "profile"
      x = 1:rows (cmap);
      htmp = plot (x,cmap(:,1),"r", x,cmap(:,2),"g", x,cmap(:,3),"b");
      set (gca, "ytick", 0:0.1:1, "xlim", [0 rows(cmap)]);
    case "composite"
      htmp = image (1:rows (cmap));
      set (gca, "ytick", []);
      colormap (cmap);
    otherwise
      error ("rgbplot: unknown STYLE '%s'", style);
  endswitch
  xlabel ("color index");

  if (nargout > 0)
    h = htmp;
  endif

endfunction


%!demo
%! clf;
%! subplot (1, 2, 1);
%!  rgbplot (ocean, "profile");
%! subplot (1, 2, 2);
%!  rgbplot (ocean, "composite");

## Test input validation
%!error <Invalid call> rgbplot ()
%!error <CMAP must be a valid colormap> rgbplot ({0 1 0})
%!error <STYLE must be a string> rgbplot ([0 1 0], 2)
%!error <unknown STYLE 'nostyle'> rgbplot ([0 1 0], "nostyle")