--- /dev/null
+## Copyright (C) 1993-2012 John W. Eaton
+## Copyright (C) 2009 VZLU Prague
+##
+## 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} {} vander (@var{c})
+## @deftypefnx {Function File} {} vander (@var{c}, @var{n})
+## Return the Vandermonde matrix whose next to last column is @var{c}.
+## If @var{n} is specified, it determines the number of columns;
+## otherwise, @var{n} is taken to be equal to the length of @var{c}.
+##
+## A Vandermonde matrix has the form:
+## @tex
+## $$
+## \left[\matrix{c_1^{n-1} & \cdots & c_1^2 & c_1 & 1 \cr
+## c_2^{n-1} & \cdots & c_2^2 & c_2 & 1 \cr
+## \vdots & \ddots & \vdots & \vdots & \vdots \cr
+## c_n^{n-1} & \cdots & c_n^2 & c_n & 1 }\right]
+## $$
+## @end tex
+## @ifnottex
+##
+## @example
+## @group
+## c(1)^(n-1) @dots{} c(1)^2 c(1) 1
+## c(2)^(n-1) @dots{} c(2)^2 c(2) 1
+## . . . . .
+## . . . . .
+## . . . . .
+## c(n)^(n-1) @dots{} c(n)^2 c(n) 1
+## @end group
+## @end example
+##
+## @end ifnottex
+## @seealso{polyfit}
+## @end deftypefn
+
+## Author: jwe
+
+function retval = vander (c, n)
+
+ if (nargin == 1)
+ n = length (c);
+ elseif (nargin != 2)
+ print_usage ();
+ endif
+
+ if (! isvector (c))
+ error ("vander: polynomial C must be a vector");
+ endif
+
+ ## avoiding many ^s appears to be faster for n >= 100.
+ retval = zeros (length (c), n, class (c));
+ d = 1;
+ c = c(:);
+ for i = n:-1:1
+ retval(:,i) = d;
+ d .*= c;
+ endfor
+
+endfunction
+
+
+%!test
+%! c = [0,1,2,3];
+%! expect = [0,0,0,1; 1,1,1,1; 8,4,2,1; 27,9,3,1];
+%! assert(vander (c), expect);
+
+%!assert (vander (1), 1)
+%!assert (vander ([1, 2, 3]), vander ([1; 2; 3]))
+%!assert (vander ([1, 2, 3]), [1, 1, 1; 4, 2, 1; 9, 3, 1])
+%!assert (vander ([1, 2, 3]*i), [-1, i, 1; -4, 2i, 1; -9, 3i, 1])
+
+%!assert(vander (2, 3), [4, 2, 1])
+%!assert(vander ([2, 3], 3), [4, 2, 1; 9, 3, 1])
+
+%!error vander ();
+%!error vander (1, 2, 3);
+%!error <polynomial C must be a vector> vander ([1, 2; 3, 4]);
+