Quaternion¶

This class represents a general quaternion, i.e. a quaternion that may not have $\left\lVert \mathbf{Q} \right\rVert = 1$ . It’s not used in NEML natively, just as a base class to the unit quaternion orientation class.

class Quaternion¶

A generic quaternion, stored as [s v1 v2 v3].

Subclassed by neml::Orientation

Public Functions

Quaternion()¶: Default constructor (manage own memory)

Quaternion(const std::vector<double> v)¶: Construct from vector (manage own memory)

Quaternion(double *v)¶: Construct from raw pointer (don’t manage memory)

Quaternion(const Quaternion &other)¶: Copy constructor.

Quaternion(const Quaternion &&other)¶: Move constructor.

virtual ~Quaternion()¶

Quaternion &operator=(const Quaternion &rhs)¶: Copy.

Quaternion &operator=(const Quaternion &&rhs)¶: Move.

bool store() const¶: Do you store your own data?

const double *quat() const¶: Raw quaternion as a const pointer.

double *data()¶: Raw quaternion as a nonconst pointer.

virtual double norm() const¶: Quaternion norm.

Quaternion opposite() const¶: Opposite.

Quaternion operator-() const¶: C++ operator opposite.

Quaternion conj() const¶: Conjugation.

Quaternion flip() const¶: Opposite scalar.

Quaternion inverse() const¶: Inversion.

Quaternion exp() const¶: Exponential map.

Quaternion log() const¶: Inverse exponential map.

Quaternion &operator*=(const Quaternion &rhs)¶: Quaternion multiplication.

Quaternion &operator*=(double scalar)¶: Scalar multiplication.

Quaternion &operator/=(const Quaternion &rhs)¶: Quaternion division.

Quaternion &operator/=(double scalar)¶: Scalar division.

Quaternion pow(double w) const¶: Power.

double dot(const Quaternion &other) const¶: Dot product, useful for various distances.

size_t hash() const¶: Hash function for quick comparisons.

void to_product_matrix(double *M) const¶: Product matrix for quaternion composition.