public void Eigenvectors_and_eigenvalues_of_satisfy_defining_equations(
[Values(1, 0.577, 0.577, 0.577, 0.577, 0.577, 0.577)] double xx,
[Values(1, 2.718, 2.718, 0.577, 0.577, 0.577, 0.577)] double yy,
[Values(1, 3.141, 3.141, 3.141, 0.577, 3.141, 0.577)] double zz,
[Values(0, 0, 1.618, 1e-40, 1e-40, 1e-60, 1e-60)] double xy,
[Values(0, 0, 2.665, 2e-40, 2e-40, 2e-60, 2e-60)] double yz,
[Values(0, 0, 4.669, 3e-40, 3e-40, 3e-60, 3e-60)] double zx)
{
var mat = new SymmetricMatrix3(xx, yy, zz, xy, yz, zx);
var loVal = mat.LowestEigenvalue();
var loVec = mat.LowestEigenvector();
Expect((mat - SymmetricMatrix3.Scalar(loVal)).Det(), Is.EqualTo(0).Within(_tolerance));
Expect(Vector3.Distance(mat * loVec, loVal * loVec), Is.LessThan(_tolerance));
}
public static void ComputeLowestEigendata(this SymmetricMatrix3 @this, out double eigenvalue, out Vector3 eigenvector)
{
eigenvalue = @this.LowestEigenvalue();
eigenvector = @this.Eigenvector(eigenvalue);
}
public static Vector3 LowestEigenvector(this SymmetricMatrix3 @this)
{
return(@this.Eigenvector(@this.LowestEigenvalue()));
}