title: Intersection between two geographic lines
body: <p>I'm using the <a href="https://dotspatial.codeplex.com/" rel="nofollow">DotSpatial</a> C# library and I'm trying to use the following code to try to find the intersection point between two lines (I know they do intersect)</p>
  
  <pre><code>var geoproj = DotSpatial.Projections.KnownCoordinateSystems.Geographic.World.WGS1984;
  
  var d1 = new FeatureSet { Projection = geoproj };
  //var c1 = new Coordinate(31.877484, 34.736723);
  //var c2 = new Coordinate(31.879607, 34.732362);
  var c1 = new Coordinate(0, -1);
  var c2 = new Coordinate(0, 1);
  var line1 = new LineString(new[] { c1, c2 });
  d1.AddFeature(line1);
  
  var d2 = new FeatureSet { Projection = geoproj };
  //var c3 = new Coordinate(31.882391, 34.73352);
  //var c4 = new Coordinate(31.875502, 34.734851);
  var c3 = new Coordinate(-1, 0);
  var c4 = new Coordinate(1, 0);
  var line2 = new LineString(new[] { c3, c4 });
  d2.AddFeature(line2);
  
  var inters = d1.Intersection(d2, FieldJoinType.All, null);
  var feats = inters.Features;
  foreach (var feat in feats)
  {
      Console.WriteLine("{0}", feat.ToString());
  }
  </code></pre>
  
  <p>The resulting feature set is always empty.</p>
  
  <p>What am I doing wrong?</p>
  
  <p>I also tried to swap the X and Y components for each coordinate (in case the first was assumed to be the longitude instead of the latitude)</p>
  
  <p>Thanks!</p>
  
  <p><strong>EDIT:</strong> As per weston's comment below, I've changed the coordinates of the two lines to more obviously intersecting ones. The result is the same.</p>