update packages

[CreaPhase.git] / octave_packages / m / image / ocean.m

diff --git a/octave_packages/m/image/ocean.m b/octave_packages/m/image/ocean.m
new file mode 100644 (file)
index 0000000..a90eb2a
--- /dev/null
+++ b/octave_packages/m/image/ocean.m
@@ -0,0 +1,65 @@
+## Copyright (C) 1994-2012 John W. Eaton
+##
+## 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} {@var{map} =} ocean ()
+## @deftypefnx {Function File} {@var{map} =} ocean (@var{n})
+## Create color colormap.  This colormap varies from black to white with shades
+## of blue.
+## The argument @var{n} must be a scalar.
+## If unspecified, the length of the current colormap, or 64, is used.
+## @end deftypefn
+
+## Author: Tony Richardson <arichard@stark.cc.oh.us>
+## Created: July 1994
+## Adapted-By: jwe
+
+function map = ocean (n)
+
+  if (nargin == 0)
+    n = rows (colormap);
+  elseif (nargin == 1)
+    if (! isscalar (n))
+      error ("ocean: argument must be a scalar");
+    endif
+  else
+    print_usage ();
+  endif
+
+  cutin = fix (n/3);
+
+  dr = (n - 1) / cutin;
+
+  r = prepad ([0:dr:(n-1)], n)';
+
+  dg = (n - 1) / (2 * cutin);
+
+  g = prepad([0:dg:(n-1)], n)';
+
+  b = [0:(n-1)]';
+
+  map = [ r, g, b ] / (n - 1);
+
+endfunction
+
+%!demo
+%! ## Show the 'ocean' colormap as an image
+%! image (1:64, linspace (0, 1, 64), repmat (1:64, 64, 1)')
+%! axis ([1, 64, 0, 1], "ticy", "xy")
+%! colormap (ocean (64))
+