Ordinary Line

Author

Eric W. Weisstein
November 15, 2005

This notebook downloaded from http://mathworld.wolfram.com/notebooks/ComputationalGeometry/OrdinaryLine.nb.

For more information, see Eric's MathWorld entry http://mathworld.wolfram.com/OrdinaryLine.html.

©2005 Wolfram Research, Inc. except for portions noted otherwise

Finschi and Fukuda Counterexample

(pts={{-1,-1},{0,-1/2},{1-2/Sqrt[5],-(1/Sqrt[5])},
{1/3, -1/3}, {0, -3/2 + Sqrt[5]/2}, {-1 + 2/Sqrt[5], -(1/Sqrt[5])},
{0, 0}, {-(1/Sqrt[5]), -(1/Sqrt[5])}, {1, -1}})//Length

Show[Graphics[{PointSize[.02],
{Red,Point/@pts[[{1,2,8,9}]]},
{Green,Point/@pts[[{3,4,5,6,7}]]},
Map
}
],AspectRatio->Automatic,PlotRange->All]