% -*- texinfo -*-
% @deftypefn {Function File} {[@var{g}, @var{y}] =} planerot (@var{x})
% Given a two-element column vector, returns the
% @tex
% $2 \times 2$ orthogonal matrix
% @end tex
% @ifnottex
% 2 by 2 orthogonal matrix
% @end ifnottex
% @var{G} such that
% @code{@var{y} = @var{g} * @var{x}} and @code{@var{y}(2) = 0}.
% @seealso{givens}
% @end deftypefn