function [ x, y, w ] = rule18 ( )

%*****************************************************************************80
%
%% RULE18 returns the rule of degree 18.
%
%  Discussion:
%
%    Order 18 (67 pts)
%    1/6 data for 18-th order quadrature with 15 nodes.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    26 June 2014
%
%  Author:
%
%    Original FORTRAN77 version by Hong Xiao, Zydrunas Gimbutas.
%    This MATLAB version by John Burkardt.
%
%  Parameters:
%
%    Output, real X(*), Y(*), the coordinates of the nodes.
%
%    Output, real W(*), the weights.
%
  x = [ ...
      -0.13948489081933204088461180178994, ...
       0.00000000000000000000000000000000, ...
       0.00000000000000000000000000000000, ...
      -0.89294878385120099482738372845036, ...
       0.00000000000000000000000000000000, ...
      -0.34186434923523414986986916455812, ...
      -0.47648266163227498302335864700291, ...
       0.00000000000000000000000000000000, ...
      -0.57691929083982134519411643537248, ...
       0.00000000000000000000000000000000, ...
       0.00000000000000000000000000000000, ...
      -0.31378647708219846613556828441497, ...
      -0.16617683797609618890338301653712, ...
      -0.72011081467827938658866318769494, ...
       0.00000000000000000000000000000000 ];
  y = [ ... ...
      -0.42072604091782665082295117027375, ...
      -0.49046440452670875509062398243114, ...
       0.62940934145837335576901873813141, ...
      -0.55570148308783861437134955410860, ...
       0.00000000000000000000000000000000, ...
      -0.48379919937747237041994289927636, ...
      -0.55915504286023151615285736575981, ...
      -0.26927767315911711440578206048817, ...
      -0.46282281236309048295631522905634, ...
       0.23458453920186008350135824349789, ...
       0.11416791732161437494841337947029E+01, ...
      -0.31915880712448193443612017530713, ...
      -0.55709943481991491343285204410962, ...
      -0.55252734012256597819639469738327, ...
       0.90376550142496547719360163488612 ];
  w = [ ... ...
       0.20173122273677479015897043873638E-01, ...
       0.86249091344656329557281505991774E-02, ...
       0.13370218870435472743618008520977E-01, ...
       0.55505642264323721863858554667335E-02, ...
       0.67445549565863583016393815247161E-02, ...
       0.21538746762008261153428035301757E-01, ...
       0.10173035336419548391103790096248E-01, ...
       0.22025810771933006688763669533528E-01, ...
       0.22256988236841747085623568927686E-01, ...
       0.20475740472311754752083054066923E-01, ...
       0.35007938360486604839471917528428E-03, ...
       0.36314280849967402171385914715287E-01, ...
       0.12616049305635046682659603780667E-01, ...
       0.10057049329246148211330983846490E-01, ...
       0.90745189158503137484947042037209E-02 ];

  return
end
