% -*- texinfo -*-
% @deftypefn {Function File} {@var{a}} = lauchli (@var{n})
% @deftypefnx {Function File} {@var{a}} = lauchli (@var{n},@var{mu})
% Creates the matrix [ ones(1,@var{n}); @var{mu}*eye(@var{n}) ]
% The value @var{mu} defaults to sqrt(eps).
% This is an ill-conditioned system for testing the
% accuracy of the QR routine.
%
% @example
% @group
% A = lauchli(15);
% [Q, R] = qr(A);
% norm(Q*R - A)
% norm(Q'*Q - eye(rows(Q)))
% @end group
% @end example
% @end deftypefn
% @seealso {ones,zeros,eye}