public void GeometricMedianReturnsThePointInsideTriangleFormedByRemainingPointsOnConcaveQuadrilateralTest()
{
// Create sample points that makes a Concave Quadrilateral
var samplePoints = new List <Point>
{
//Point inside triangle formed by remaining 3 points
Point.ByCoordinates(7, 8),
//Remaining point
Point.ByCoordinates(9.5, 7.2),
Point.ByCoordinates(8, 4.8),
Point.ByCoordinates(6, 9)
};
// Get the geometric median of the Concave Quadrilateral sample points
// which is the point inside the triangle formed by remaining 3 points
Point geometricMedianPoint = Adjacency.GeometricMedianOfPoints(samplePoints);
// Check if both X and Y of the geometric median is the same as X and Y of the
// point inside the triangle formed by the remaining points (samplePoints[0]).
Assert.AreEqual(samplePoints[0].X, geometricMedianPoint.X);
Assert.AreEqual(samplePoints[0].Y, geometricMedianPoint.Y);
// Dispose unused geometry.
samplePoints.ForEach(p => p.Dispose());
geometricMedianPoint.Dispose();
}
public void GeometricMedianReturnsFermatPointOnAcuteTriangleTest()
{
// Create sample points that makes a Acute triangle
var samplePoints = new List <Point>
{
Point.ByCoordinates(5, 5),
Point.ByCoordinates(9.5, 4.2),
Point.ByCoordinates(8, 3)
};
// Get the geometric median of the Acute triangles sample points
// Also known as the Fermat Point
Point fermatPoint = Adjacency.GeometricMedianOfPoints(samplePoints);
// Create vectors from the fermat point to two arbitrary points in the sample points list.
var vectors = new List <Vector>
{
Vector.ByTwoPoints(fermatPoint, samplePoints[0]),
Vector.ByTwoPoints(fermatPoint, samplePoints[1]),
};
// Getting the angle between the two vectors just created.
// This angle should always be 120 degrees in a Acute triangle.
var testAngle = vectors[0].AngleWithVector(vectors[1]);
// Checking if the angle is equal to 120 degrees.
Assert.AreEqual(120.0, Math.Round(testAngle, 1));
// Dispose unused geometry
samplePoints.ForEach(p => p.Dispose());
fermatPoint.Dispose();
vectors.ForEach(p => p.Dispose());
}
public void GeometricMedianReturnVertexAtAngleEqualToOrAbove120OnObtuseTriangleTest()
{
// Create sample points that makes a Obtuse triangle
var samplePoints = new List <Point>
{
Point.ByCoordinates(0, 0),
Point.ByCoordinates(10, 5),
// Vertex at angle > 120
Point.ByCoordinates(5, 0)
};
// Get the geometric median point
Point vertexOnObtuseAngle = Adjacency.GeometricMedianOfPoints(samplePoints);
// Check if both X and Y of the geometric median is the same as X and Y of the vertex at angle > 120 in the obtuse triangle.
Assert.AreEqual(samplePoints[2].X, vertexOnObtuseAngle.X);
Assert.AreEqual(samplePoints[2].Y, vertexOnObtuseAngle.Y);
// Dispose unused geometry
samplePoints.ForEach(p => p.Dispose());
vertexOnObtuseAngle.Dispose();
}
public void GeometricMedianCalculatesForPointsOnLine()
{
// Create sample points that are colinear and symmetrical to geometric median point
var sample4Points = new List <Point>
{
Point.ByCoordinates(260, 600),
Point.ByCoordinates(285, 600),
Point.ByCoordinates(310, 600),
Point.ByCoordinates(335, 600)
};
var expectedPoint = Point.ByCoordinates(297.5, 600);
// also check situations when we have more than 4 points and they are not symmetrical
// note we have to duplicate points declaration due to LibG
var sample6Points = new List <Point>
{
Point.ByCoordinates(250, 600),
Point.ByCoordinates(255, 600),
Point.ByCoordinates(285, 600),
Point.ByCoordinates(310, 600),
Point.ByCoordinates(335, 600),
Point.ByCoordinates(350, 600)
};
// compute geometric median for both cases
Point geometricMedian4Point = Adjacency.GeometricMedianOfPoints(sample4Points);
Point geometricMedian6Point = Adjacency.GeometricMedianOfPoints(sample6Points);
// Check if both X and Y of the geometric median is the same
// as X and Y of the midpoint on the line
Assert.AreEqual(expectedPoint, geometricMedian4Point);
Assert.AreEqual(expectedPoint, geometricMedian6Point);
// Dispose unused geometry.
sample4Points.ForEach(p => p.Dispose());
sample6Points.ForEach(p => p.Dispose());
geometricMedian4Point.Dispose();
geometricMedian6Point.Dispose();
}
public void GeometricMedianCalculatesForTriangle()
{
// Create sample points that are colinear and symmetrical to geometric median point
var trianglePoints = new List <Point>
{
Point.ByCoordinates(10, 0),
Point.ByCoordinates(0, 0),
Point.ByCoordinates(5, 8.66)
};
var expectedPoint = Point.ByCoordinates(5, 2.8867513459);
// compute geometric median
Point geometricMedianTriangle = Adjacency.GeometricMedianOfPoints(trianglePoints);
// Check if both X and Y of the geometric median is the same
// as X and Y of the midpoint on the line
Assert.IsTrue(expectedPoint.X.AlmostEqualTo(geometricMedianTriangle.X));
Assert.IsTrue(expectedPoint.Y.AlmostEqualTo(geometricMedianTriangle.Y));
Assert.IsTrue(expectedPoint.Z.AlmostEqualTo(geometricMedianTriangle.Z));
// Dispose unused geometry.
trianglePoints.ForEach(p => p.Dispose());
geometricMedianTriangle.Dispose();
}