tvals := [-1.570796327, -1.178097245, -.7853981635, -.3926990818, 0.,
  .3926990818, .7853981635, 1.178097245, 1.570796327, 1.963495409,
  2.356194490, 2.748893572, 3.141592654, 3.534291736, 3.926990818,
  4.319689899, 4.712388981, 5.105088063, 5.497787144, 5.890486226,
  6.283185308, 6.675884390, 7.068583472, 7.461282553, 7.853981635,
  8.246680717, 8.639379798, 9.032078880, 9.424777962, 9.817477044,  
  10.21017613, 10.60287521, 10.99557429, 11.38827337, 11.78097245,
  12.17367153, 12.56637062, 12.95906970, 13.35176878, 13.74446786,
  14.13716694]; 
epipts := [[-3.535533907, -10.53553390], [5.456635192, -10.62450479],
  [9.569145131, -3.036330307], [5.491705118, 2.225142374], [2., 0.],
  [5.491705118, -2.225142374], [9.569145131, 3.036330307],
  [5.456635192, 10.62450479], [-3.535533907,10.53553390],
  [-6.836132085, 3.689305552], [-3.036330310, .330349805],
  [-1.563230326, 3.654235638], [-7.000000012, 4.999999997],
  [-11.37108313, -1.703332452],[-6.863164624, -9.569145137],
  [1.478564049, -9.245007874], [3.535533914, -3.464466099],
  [-.99067144e-1, -2.309808671], [.330349800, -6.863164614],
  [7.442608343, -7.582710424], [12., .3010013132e-7],
  [7.442608340, 7.582710435], [.330349793, 6.863164623],
  [-.99067114e-1, 2.309808649], [3.535533903, 3.464466098],
  [1.478564012, 9.245007910], [-6.863164629, 9.569145129],
  [-11.37108313, 1.703332394], [-6.999999963, -5.000000009],
  [-1.563230319, -3.654235640], [-3.036330396, -.330349786],
  [-6.836132116, -3.689305655], [-3.535533841, -10.53553395],
  [5.456635227, -10.62450476], [9.569145124, -3.036330303],
  [5.491705131, 2.225142362],[2.000000000, -.5922868398e-7],
  [5.491705174, -2.225142364], [9.569145135, 3.036330354],
  [5.456635180, 10.62450480], [-3.535533884, 10.53553392]];