function chebyshev1_rule ( order, output )

%% LEGENDRE_RULE generates a Gauss-Chebyshev type 1 quadrature rule.
%
%  Discussion:
%
%    This program computes a standard Gauss-Chebyshev type 1 quadrature rule
%    and writes it to a file.
%
%    The user specifies:
%    * the ORDER (number of points) in the rule
%    * the root name of the output files.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    01 March 2008
%
%  Author:
%
%    John Burkardt
%
  timestamp;
  fprintf ( 1, '\n' );
  fprintf ( 1, 'CHEBYSHEV1_RULE\n' );
  fprintf ( 1, '  MATLAB version\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  Compute a Gauss-Chebyshev type 1 rule for approximating\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '    Integral ( -1 <= x <= +1 ) f(x)  / sqrt(1-x^2) dx\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  of order ORDER.\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  The user specifies ORDER and OUTPUT.\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  OUTPUT is:\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  "C++" for printed C++ output;\n' );
  fprintf ( 1, '  "F77" for printed Fortran77 output;\n' );
  fprintf ( 1, '  "F90" for printed Fortran90 output;\n' );
  fprintf ( 1, '  "MAT" for printed MATLAB output;\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  or:\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '  "filename" to generate 3 files:\n' );
  fprintf ( 1, '\n' );
  fprintf ( 1, '    filename_w.txt - the weight file\n' );
  fprintf ( 1, '    filename_x.txt - the abscissa file.\n' );
  fprintf ( 1, '    filename_r.txt - the region file.\n' );
%
%  Get the order.
%
  if ( 1 <= nargin )

  else
    order = input ( '  Enter the rule order ORDER.' );
  end

  fprintf ( 1,  '\n' );
  fprintf ( 1,  '  The requested order of the rule is %d\n', order );
%
%  Get the output option or quadrature file root name:
%
  if ( 2 <= nargin )

  else

    fprintf ( 1,  '\n' );
    fprintf ( 1,  '  OUTPUT specifies printed output in the form of\n' );
    fprintf ( 1,  '  ''C++'', ''F77'', ''F90'', ''MAT'',\n' );
    fprintf ( 1,  '  or else the ''root name'' of a set of quadrature files).\n' );

    output = input ( '  Enter the value of OUTPUT as a quoted string:' );

  end

  fprintf ( 1, '\n' );
  fprintf ( 1, '  OUTPUT option = "%s".\n', output );
%
%  Construct the rule and output it.
%
  chebyshev1_handle ( order, output );

  fprintf ( 1,  '\n' );
  fprintf ( 1,  'CHEBYSHEV1_RULE:\n' );
  fprintf ( 1,  '  Normal end of execution.\n' );
  fprintf ( 1,  '\n' );
  timestamp;