public void Matrix3dDeterminantTest()
{
Matrix3d m = new Matrix3d();
m.A00 = 6;
m.A10 = 4;
m.A20 = 2;
m.A01 = 1;
m.A11 = -2;
m.A21 = 8;
m.A02 = 1;
m.A12 = 5;
m.A22 = 7;
Assert.AreEqual(-306, m.Determinate());
}
private double GetDeterminant(Point3d p, VectorField f)
{
var dx = 1.0; var dy = dx; var dz = dx;
var px = new Point3d(dx, 0, 0);
var py = new Point3d(0, dy, 0);
var pz = new Point3d(0, 0, dz);
Matrix3d m = new Matrix3d();
m.A00 = (f.X[p + px / 2] - f.X[p - px / 2]) / dx;
m.A01 = (f.X[p + py / 2] - f.X[p - py / 2]) / dy;
m.A02 = (f.X[p + pz / 2] - f.X[p - pz / 2]) / dz;
m.A10 = (f.Y[p + px / 2] - f.X[p - px / 2]) / dx;
m.A11 = (f.Y[p + py / 2] - f.X[p - py / 2]) / dy;
m.A12 = (f.Y[p + pz / 2] - f.X[p - pz / 2]) / dz;
m.A20 = (f.Z[p + px / 2] - f.X[p - px / 2]) / dx;
m.A21 = (f.Z[p + py / 2] - f.X[p - py / 2]) / dy;
m.A22 = (f.Z[p + pz / 2] - f.X[p - pz / 2]) / dz;
return(m.Determinate());
}
