## Copyright (C) 1998 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 2, 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, write to the Free
## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
## 02110-1301, USA.
## -*- texinfo -*-
## @deftypefn {Function File} {} dot (@var{x}, @var{y}, @var{dim})
## Computes the dot product of two vectors. If @var{x} and @var{y}
## are matrices, calculate the dot-product along the first
## non-singleton dimension. If the optional argument @var{dim} is
## given, calculate the dot-product along this dimension.
## @end deftypefn
## Author: jwe
function z = dot (x, y, dim)
if (nargin != 2 && nargin != 3)
print_usage ();
endif
if (nargin < 3)
if (isvector (x))
x = x(:);
endif
if (isvector (y))
y = y(:);
endif
if (! size_equal (x, y))
error ("dot: sizes of arguments must match")
endif
z = sum(x .* y);
else
if (! size_equal (x, y))
error ("dot: sizes of arguments must match")
endif
z = sum(x .* y, dim);
endif
endfunction
/*
@GROUP
LinearAlgebra
@SYNTAX
dot()
@DOC
.
@EXAMPLES
@NOTES
@SEE
*/