TEST_F(QuaternionTest, default_quaternion_is_identity_quaternion)
{
const Math::Quaternion<double> quat;
EXPECT_EQ(1, quat.w());
EXPECT_EQ(0, quat.x());
EXPECT_EQ(0, quat.y());
EXPECT_EQ(0, quat.z());
}
void OnlineRotHec::addMeasurement( const Math::Quaternion& q, const Math::Quaternion& r )
{
// make sure the signs of both w's are equal
const double nq = q.w() < 0 ? -1 : 1;
const double nr = r.w() < 0 ? -1 : 1;
Math::ErrorVector< double, 3 > kalmanMeasurement;
kalmanMeasurement.value( 0 ) = r.x() * nr - q.x() * nq;
kalmanMeasurement.value( 1 ) = r.y() * nr - q.y() * nq;
kalmanMeasurement.value( 2 ) = r.z() * nr - q.z() * nq;
kalmanMeasurement.covariance = Math::Matrix< double, 3, 3 >::identity();
// do the filter update
Math::Matrix< double, 3, 3 > h;
skewMatrix( h, Math::Vector< double, 3 >( q.x() * nq + r.x() * nr, q.y() * nq + r.y() * nr, q.z() * nq + r.z() * nr ) );
Tracking::kalmanMeasurementUpdate< 3, 3 >( m_state, Math::Function::LinearFunction< 3, 3, double >( h ),
kalmanMeasurement, 0, m_state.value.size() );
}
Math::Quaternion<double> create_quaternion_from_small_real_component(const Math::Matrix4d& matrix)
{
Math::Quaternion<double> result;
result.w() = 0.5 * std::sqrt(matrix_trace(matrix));
result.x() = 0.5 * std::sqrt(matrix(0,0) - matrix(1,1) - matrix(2,2) + matrix(3,3));
result.y() = 0.5 * std::sqrt(-matrix(0,0) + matrix(1,1) - matrix(2,2) + matrix(3,3));
result.z() = 0.5 * std::sqrt(-matrix(0,0) - matrix(1,1) + matrix(2,2) + matrix(3,3));
return result;
}
Math::Quaternion<double> create_quaternion_from_large_real_component(const Math::Matrix4d& matrix)
{
Math::Quaternion<double> result;
result.w() = 0.5 * std::sqrt(matrix_trace(matrix));
result.x() = 0.25 *(matrix(2,1) - matrix(1,2))/result.w();
result.y() = 0.25 *(matrix(0,2) - matrix(2,0))/result.w();
result.z() = 0.25 *(matrix(1,0) - matrix(0,1))/result.w();
return result;
}
Math::Matrix4d make_matrix_from_quaternion(const Math::Quaternion<double>& quat)
{
Math::Matrix4d matrix;
const auto s = 2.0 / quaternion_norm(quat);
matrix(0,0) -= s *(quat.y() * quat.y() + quat.z() * quat.z());
matrix(0,1) += s *(quat.x() * quat.y() - quat.w() * quat.z());
matrix(0,2) += s *(quat.x() * quat.z() + quat.w() * quat.y());
matrix(1,0) += s *(quat.x() * quat.y() + quat.w() * quat.z());
matrix(1,1) -= s *(quat.x() * quat.x() + quat.z() * quat.z());
matrix(1,2) += s *(quat.y() * quat.z() - quat.w() * quat.x());
matrix(2,0) += s *(quat.x() * quat.z() - quat.w() * quat.y());
matrix(2,1) += s *(quat.y() * quat.z() + quat.w() * quat.x());
matrix(2,2) -= s *(quat.x() * quat.x() + quat.y() * quat.y());
return matrix;
}