[def __R ['[*R]]] [def __C ['[*C]]] [def __H ['[*H]]] [def __O ['[*O]]] [def __R3 ['[*'''R3''']]] [def __R4 ['[*'''R4''']]] [def __quadrulple ('''α,β,γ,δ''')] [def __quat_formula ['[^q = '''α + βi + γj + δk''']]] [def __quat_complex_formula ['[^q = ('''α + βi) + (γ + δi)j''' ]]] [def __not_equal ['[^xy '''≠''' yx]]] [section Quaternions] [section Overview] Quaternions are a relative of complex numbers. Quaternions are in fact part of a small hierarchy of structures built upon the real numbers, which comprise only the set of real numbers (traditionally named __R), the set of complex numbers (traditionally named __C), the set of quaternions (traditionally named __H) and the set of octonions (traditionally named __O), which possess interesting mathematical properties (chief among which is the fact that they are ['division algebras], ['i.e.] where the following property is true: if ['[^y]] is an element of that algebra and is [*not equal to zero], then ['[^yx = yx']], where ['[^x]] and ['[^x']] denote elements of that algebra, implies that ['[^x = x']]). Each member of the hierarchy is a super-set of the former. One of the most important aspects of quaternions is that they provide an efficient way to parameterize rotations in __R3 (the usual three-dimensional space) and __R4. In practical terms, a quaternion is simply a quadruple of real numbers __quadrulple, which we can write in the form __quat_formula, where ['[^i]] is the same object as for complex numbers, and ['[^j]] and ['[^k]] are distinct objects which play essentially the same kind of role as ['[^i]]. An addition and a multiplication is defined on the set of quaternions, which generalize their real and complex counterparts. The main novelty here is that [*the multiplication is not commutative] (i.e. there are quaternions ['[^x]] and ['[^y]] such that __not_equal). A good mnemotechnical way of remembering things is by using the formula ['[^i*i = j*j = k*k = -1]]. Quaternions (and their kin) are described in far more details in this other [@../../libs/math/quaternion/TQE.pdf document] (with [@../../libs/math/quaternion/TQE_EA.pdf errata and addenda]). Some traditional constructs, such as the exponential, carry over without too much change into the realms of quaternions, but other, such as taking a square root, do not. [endsect] [section Header File] The interface and implementation are both supplied by the header file [@../../boost/math/quaternion.hpp quaternion.hpp]. [endsect] [section Synopsis] namespace boost{ namespace math{ template class ``[link boost_math.quaternions.template_class_quaternion quaternion]``; template<> class ``[link boost_math.quaternions.quaternion_specializations quaternion]``; template<> class ``[link boost_math.quaternion_double quaternion]``; template<> class ``[link boost_math.quaternion_long_double quaternion]``; // operators template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_addition_operators operator +]`` (T const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_addition_operators operator +]`` (quaternion const & lhs, T const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_addition_operators operator +]`` (::std::complex const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_addition_operators operator +]`` (quaternion const & lhs, ::std::complex const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_addition_operators operator +]`` (quaternion const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_subtraction_operators operator -]`` (T const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_subtraction_operators operator -]`` (quaternion const & lhs, T const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_subtraction_operators operator -]`` (::std::complex const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_subtraction_operators operator -]`` (quaternion const & lhs, ::std::complex const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_subtraction_operators operator -]`` (quaternion const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_multiplication_operators operator *]`` (T const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_multiplication_operators operator *]`` (quaternion const & lhs, T const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_multiplication_operators operator *]`` (::std::complex const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_multiplication_operators operator *]`` (quaternion const & lhs, ::std::complex const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_multiplication_operators operator *]`` (quaternion const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_division_operators operator /]`` (T const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_division_operators operator /]`` (quaternion const & lhs, T const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_division_operators operator /]`` (::std::complex const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_division_operators operator /]`` (quaternion const & lhs, ::std::complex const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.binary_division_operators operator /]`` (quaternion const & lhs, quaternion const & rhs); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.unary_plus operator +]`` (quaternion const & q); template quaternion ``[link boost_math.quaternions.quaternion_non_member_operators.unary_minus operator -]`` (quaternion const & q); template bool ``[link boost_math.quaternions.quaternion_non_member_operators.equality_operators operator ==]`` (T const & lhs, quaternion const & rhs); template bool ``[link boost_math.quaternions.quaternion_non_member_operators.equality_operators operator ==]`` (quaternion const & lhs, T const & rhs); template bool ``[link boost_math.quaternions.quaternion_non_member_operators.equality_operators operator ==]`` (::std::complex const & lhs, quaternion const & rhs); template bool ``[link boost_math.quaternions.quaternion_non_member_operators.equality_operators operator ==]`` (quaternion const & lhs, ::std::complex const & rhs); template bool ``[link boost_math.quaternions.quaternion_non_member_operators.equality_operators operator ==]`` (quaternion const & lhs, quaternion const & rhs); template bool ``[link boost_math.quaternions.quaternion_non_member_operators.inequality_operators operator !=]`` (T const & lhs, quaternion const & rhs); template bool ``[link boost_math.quaternions.quaternion_non_member_operators.inequality_operators operator !=]`` (quaternion const & lhs, T const & rhs); template bool ``[link boost_math.quaternions.quaternion_non_member_operators.inequality_operators operator !=]`` (::std::complex const & lhs, quaternion const & rhs); template bool ``[link boost_math.quaternions.quaternion_non_member_operators.inequality_operators operator !=]`` (quaternion const & lhs, ::std::complex const & rhs); template bool ``[link boost_math.quaternions.quaternion_non_member_operators.inequality_operators operator !=]`` (quaternion const & lhs, quaternion const & rhs); template ::std::basic_istream& ``[link boost_math.quaternions.quaternion_non_member_operators.stream_extractor operator >>]`` (::std::basic_istream & is, quaternion & q); template ::std::basic_ostream& operator ``[link boost_math.quaternions.quaternion_non_member_operators.stream_inserter operator <<]`` (::std::basic_ostream & os, quaternion const & q); // values template T ``[link boost_math.quaternions.quaternion_value_operations.real_and_unreal real]``(quaternion const & q); template quaternion ``[link boost_math.quaternions.quaternion_value_operations.real_and_unreal unreal]``(quaternion const & q); template T ``[link boost_math.quaternions.quaternion_value_operations.sup sup]``(quaternion const & q); template T ``[link boost_math.quaternions.quaternion_value_operations.l1 l1]``(quaternion const & q); template T ``[link boost_math.quaternions.quaternion_value_operations.abs abs]``(quaternion const & q); template T ``[link boost_math.quaternions.quaternion_value_operations.norm norm]``(quaternionconst & q); template quaternion ``[link boost_math.quaternions.quaternion_value_operations.conj conj]``(quaternion const & q); template quaternion ``[link boost_math.quaternions.creation_spherical spherical]``(T const & rho, T const & theta, T const & phi1, T const & phi2); template quaternion ``[link boost_math.quaternions.creation_semipolar semipolar]``(T const & rho, T const & alpha, T const & theta1, T const & theta2); template quaternion ``[link boost_math.quaternions.creation_multipolar multipolar]``(T const & rho1, T const & theta1, T const & rho2, T const & theta2); template quaternion ``[link boost_math.quaternions.creation_cylindrospherical cylindrospherical]``(T const & t, T const & radius, T const & longitude, T const & latitude); template quaternion ``[link boost_math.quaternions.creation_cylindrical cylindrical]``(T const & r, T const & angle, T const & h1, T const & h2); // transcendentals template quaternion ``[link boost_math.quaternions.quaternion_transcendentals.exp exp]``(quaternion const & q); template quaternion ``[link boost_math.quaternions.quaternion_transcendentals.cos cos]``(quaternion const & q); template quaternion ``[link boost_math.quaternions.quaternion_transcendentals.sin sin]``(quaternion const & q); template quaternion ``[link boost_math.quaternions.quaternion_transcendentals.tan tan]``(quaternion const & q); template quaternion ``[link boost_math.quaternions.quaternion_transcendentals.cosh cosh]``(quaternion const & q); template quaternion ``[link boost_math.quaternions.quaternion_transcendentals.sinh sinh]``(quaternion const & q); template quaternion ``[link boost_math.quaternions.quaternion_transcendentals.tanh tanh]``(quaternion const & q); template quaternion ``[link boost_math.quaternions.quaternion_transcendentals.pow pow]``(quaternion const & q, int n); } // namespace math } // namespace boost [endsect] [section Template Class quaternion] namespace boost{ namespace math{ template class quaternion { public: typedef T ``[link boost_math.quaternions.quaternion_member_typedefs value_type]``; explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(T const & requested_a = T(), T const & requested_b = T(), T const & requested_c = T(), T const & requested_d = T()); explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(::std::complex const & z0, ::std::complex const & z1 = ::std::complex()); template explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(quaternion const & a_recopier); T ``[link boost_math.quaternions.quaternion_member_functions.real_and_unreal_parts real]``() const; quaternion ``[link boost_math.quaternions.quaternion_member_functions.real_and_unreal_parts unreal]``() const; T ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_1]``() const; T ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_2]``() const; T ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_3]``() const; T ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_4]``() const; ::std::complex ``[link boost_math.quaternions.quaternion_member_functions.individual_complex__components C_component_1]``() const; ::std::complex ``[link boost_math.quaternions.quaternion_member_functions.individual_complex__components C_component_2]``() const; quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(quaternion const & a_affecter); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(quaternion const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(T const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(::std::complex const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(T const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(T const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(T const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(T const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(quaternion const & rhs); }; } // namespace math } // namespace boost [endsect] [section Quaternion Specializations] namespace boost{ namespace math{ template<> class quaternion { public: typedef float ``[link boost_math.quaternions.quaternion_member_typedefs value_type]``; explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(float const & requested_a = 0.0f, float const & requested_b = 0.0f, float const & requested_c = 0.0f, float const & requested_d = 0.0f); explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(::std::complex const & z0, ::std::complex const & z1 = ::std::complex()); explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(quaternion const & a_recopier); explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(quaternion const & a_recopier); float ``[link boost_math.quaternions.quaternion_member_functions.real_and_unreal_parts real]``() const; quaternion ``[link boost_math.quaternions.quaternion_member_functions.real_and_unreal_parts unreal]``() const; float ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_1]``() const; float ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_2]``() const; float ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_3]``() const; float ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_4]``() const; ::std::complex ``[link boost_math.quaternions.quaternion_member_functions.individual_complex__components C_component_1]``() const; ::std::complex ``[link boost_math.quaternions.quaternion_member_functions.individual_complex__components C_component_2]``() const; quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(quaternion const & a_affecter); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(quaternion const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(float const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(::std::complex const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(float const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(float const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(float const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(float const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(quaternion const & rhs); }; [#boost_math.quaternion_double] template<> class quaternion { public: typedef double ``[link boost_math.quaternions.quaternion_member_typedefs value_type]``; explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(double const & requested_a = 0.0, double const & requested_b = 0.0, double const & requested_c = 0.0, double const & requested_d = 0.0); explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(::std::complex const & z0, ::std::complex const & z1 = ::std::complex()); explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(quaternion const & a_recopier); explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(quaternion const & a_recopier); double ``[link boost_math.quaternions.quaternion_member_functions.real_and_unreal_parts real]``() const; quaternion ``[link boost_math.quaternions.quaternion_member_functions.real_and_unreal_parts unreal]``() const; double ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_1]``() const; double ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_2]``() const; double ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_3]``() const; double ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_4]``() const; ::std::complex ``[link boost_math.quaternions.quaternion_member_functions.individual_complex__components C_component_1]``() const; ::std::complex ``[link boost_math.quaternions.quaternion_member_functions.individual_complex__components C_component_2]``() const; quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(quaternion const & a_affecter); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(quaternion const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(double const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(::std::complex const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(double const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(double const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(double const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(double const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(quaternion const & rhs); }; [#boost_math.quaternion_long_double] template<> class quaternion { public: typedef long double ``[link boost_math.quaternions.quaternion_member_typedefs value_type]``; explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(long double const & requested_a = 0.0L, long double const & requested_b = 0.0L, long double const & requested_c = 0.0L, long double const & requested_d = 0.0L); explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(::std::complex const & z0, ::std::complex const & z1 = ::std::complex()); explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(quaternion const & a_recopier); explicit ``[link boost_math.quaternions.quaternion_member_functions.constructors quaternion]``(quaternion const & a_recopier); long double ``[link boost_math.quaternions.quaternion_member_functions.real_and_unreal_parts real]``() const; quaternion ``[link boost_math.quaternions.quaternion_member_functions.real_and_unreal_parts unreal]``() const; long double ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_1]``() const; long double ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_2]``() const; long double ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_3]``() const; long double ``[link boost_math.quaternions.quaternion_member_functions.individual_real_components R_component_4]``() const; ::std::complex ``[link boost_math.quaternions.quaternion_member_functions.individual_complex__components C_component_1]``() const; ::std::complex ``[link boost_math.quaternions.quaternion_member_functions.individual_complex__components C_component_2]``() const; quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(quaternion const & a_affecter); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(quaternion const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(long double const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.assignment_operators operator = ]``(::std::complex const & a_affecter); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(long double const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.addition_operators operator += ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(long double const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.subtraction_operators operator -= ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(long double const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.multiplication_operators operator *= ]``(quaternion const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(long double const & rhs); quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(::std::complex const & rhs); template quaternion& ``[link boost_math.quaternions.quaternion_member_functions.division_operators operator /= ]``(quaternion const & rhs); }; } // namespace math } // namespace boost [endsect] [section Quaternion Member Typedefs] [*value_type] Template version: typedef T value_type; Float specialization version: typedef float value_type; Double specialization version: typedef double value_type; Long double specialization version: typedef long double value_type; These provide easy acces to the type the template is built upon. [endsect] [section Quaternion Member Functions] [h3 Constructors] Template version: explicit quaternion(T const & requested_a = T(), T const & requested_b = T(), T const & requested_c = T(), T const & requested_d = T()); explicit quaternion(::std::complex const & z0, ::std::complex const & z1 = ::std::complex()); template explicit quaternion(quaternion const & a_recopier); Float specialization version: explicit quaternion(float const & requested_a = 0.0f, float const & requested_b = 0.0f, float const & requested_c = 0.0f, float const & requested_d = 0.0f); explicit quaternion(::std::complex const & z0,::std::complex const & z1 = ::std::complex()); explicit quaternion(quaternion const & a_recopier); explicit quaternion(quaternion const & a_recopier); Double specialization version: explicit quaternion(double const & requested_a = 0.0, double const & requested_b = 0.0, double const & requested_c = 0.0, double const & requested_d = 0.0); explicit quaternion(::std::complex const & z0, ::std::complex const & z1 = ::std::complex()); explicit quaternion(quaternion const & a_recopier); explicit quaternion(quaternion const & a_recopier); Long double specialization version: explicit quaternion(long double const & requested_a = 0.0L, long double const & requested_b = 0.0L, long double const & requested_c = 0.0L, long double const & requested_d = 0.0L); explicit quaternion( ::std::complex const & z0, ::std::complex const & z1 = ::std::complex()); explicit quaternion(quaternion const & a_recopier); explicit quaternion(quaternion const & a_recopier); A default constructor is provided for each form, which initializes each component to the default values for their type (i.e. zero for floating numbers). This constructor can also accept one to four base type arguments. A constructor is also provided to build quaternions from one or two complex numbers sharing the same base type. The unspecialized template also sports a templarized copy constructor, while the specialized forms have copy constructors from the other two specializations, which are explicit when a risk of precision loss exists. For the unspecialized form, the base type's constructors must not throw. Destructors and untemplated copy constructors (from the same type) are provided by the compiler. Converting copy constructors make use of a templated helper function in a "detail" subnamespace. [h3 Other member functions] [h4 Real and Unreal Parts] T real() const; quaternion unreal() const; Like complex number, quaternions do have a meaningful notion of "real part", but unlike them there is no meaningful notion of "imaginary part". Instead there is an "unreal part" which itself is a quaternion, and usually nothing simpler (as opposed to the complex number case). These are returned by the first two functions. [h4 Individual Real Components] T R_component_1() const; T R_component_2() const; T R_component_3() const; T R_component_4() const; A quaternion having four real components, these are returned by these four functions. Hence real and R_component_1 return the same value. [h4 Individual Complex Components] ::std::complex C_component_1() const; ::std::complex C_component_2() const; A quaternion likewise has two complex components, and as we have seen above, for any quaternion __quat_formula we also have __quat_complex_formula. These functions return them. The real part of `q.C_component_1()` is the same as `q.real()`. [h3 Quaternion Member Operators] [h4 Assignment Operators] quaternion& operator = (quaternion const & a_affecter); template quaternion& operator = (quaternion const& a_affecter); quaternion& operator = (T const& a_affecter); quaternion& operator = (::std::complex const& a_affecter); These perform the expected assignment, with type modification if necessary (for instance, assigning from a base type will set the real part to that value, and all other components to zero). For the unspecialized form, the base type's assignment operators must not throw. [h4 Addition Operators] quaternion& operator += (T const & rhs) quaternion& operator += (::std::complex const & rhs); template quaternion& operator += (quaternion const & rhs); These perform the mathematical operation `(*this)+rhs` and store the result in `*this`. The unspecialized form has exception guards, which the specialized forms do not, so as to insure exception safety. For the unspecialized form, the base type's assignment operators must not throw. [h4 Subtraction Operators] quaternion& operator -= (T const & rhs) quaternion& operator -= (::std::complex const & rhs); template quaternion& operator -= (quaternion const & rhs); These perform the mathematical operation `(*this)-rhs` and store the result in `*this`. The unspecialized form has exception guards, which the specialized forms do not, so as to insure exception safety. For the unspecialized form, the base type's assignment operators must not throw. [h4 Multiplication Operators] quaternion& operator *= (T const & rhs) quaternion& operator *= (::std::complex const & rhs); template quaternion& operator *= (quaternion const & rhs); These perform the mathematical operation `(*this)*rhs` [*in this order] (order is important as multiplication is not commutative for quaternions) and store the result in `*this`. The unspecialized form has exception guards, which the specialized forms do not, so as to insure exception safety. For the unspecialized form, the base type's assignment operators must not throw. [h4 Division Operators] quaternion& operator /= (T const & rhs) quaternion& operator /= (::std::complex const & rhs); template quaternion& operator /= (quaternion const & rhs); These perform the mathematical operation `(*this)*inverse_of(rhs)` [*in this order] (order is important as multiplication is not commutative for quaternions) and store the result in `*this`. The unspecialized form has exception guards, which the specialized forms do not, so as to insure exception safety. For the unspecialized form, the base type's assignment operators must not throw. [endsect] [section Quaternion Non-Member Operators] [h4 Unary Plus] template quaternion operator + (quaternion const & q); This unary operator simply returns q. [h4 Unary Minus] template quaternion operator - (quaternion const & q); This unary operator returns the opposite of q. [h4 Binary Addition Operators] template quaternion operator + (T const & lhs, quaternion const & rhs); template quaternion operator + (quaternion const & lhs, T const & rhs); template quaternion operator + (::std::complex const & lhs, quaternion const & rhs); template quaternion operator + (quaternion const & lhs, ::std::complex const & rhs); template quaternion operator + (quaternion const & lhs, quaternion const & rhs); These operators return `quaternion(lhs) += rhs`. [h4 Binary Subtraction Operators] template quaternion operator - (T const & lhs, quaternion const & rhs); template quaternion operator - (quaternion const & lhs, T const & rhs); template quaternion operator - (::std::complex const & lhs, quaternion const & rhs); template quaternion operator - (quaternion const & lhs, ::std::complex const & rhs); template quaternion operator - (quaternion const & lhs, quaternion const & rhs); These operators return `quaternion(lhs) -= rhs`. [h4 Binary Multiplication Operators] template quaternion operator * (T const & lhs, quaternion const & rhs); template quaternion operator * (quaternion const & lhs, T const & rhs); template quaternion operator * (::std::complex const & lhs, quaternion const & rhs); template quaternion operator * (quaternion const & lhs, ::std::complex const & rhs); template quaternion operator * (quaternion const & lhs, quaternion const & rhs); These operators return `quaternion(lhs) *= rhs`. [h4 Binary Division Operators] template quaternion operator / (T const & lhs, quaternion const & rhs); template quaternion operator / (quaternion const & lhs, T const & rhs); template quaternion operator / (::std::complex const & lhs, quaternion const & rhs); template quaternion operator / (quaternion const & lhs, ::std::complex const & rhs); template quaternion operator / (quaternion const & lhs, quaternion const & rhs); These operators return `quaternion(lhs) /= rhs`. It is of course still an error to divide by zero... [h4 Equality Operators] template bool operator == (T const & lhs, quaternion const & rhs); template bool operator == (quaternion const & lhs, T const & rhs); template bool operator == (::std::complex const & lhs, quaternion const & rhs); template bool operator == (quaternion const & lhs, ::std::complex const & rhs); template bool operator == (quaternion const & lhs, quaternion const & rhs); These return true if and only if the four components of `quaternion(lhs)` are equal to their counterparts in `quaternion(rhs)`. As with any floating-type entity, this is essentially meaningless. [h4 Inequality Operators] template bool operator != (T const & lhs, quaternion const & rhs); template bool operator != (quaternion const & lhs, T const & rhs); template bool operator != (::std::complex const & lhs, quaternion const & rhs); template bool operator != (quaternion const & lhs, ::std::complex const & rhs); template bool operator != (quaternion const & lhs, quaternion const & rhs); These return true if and only if `quaternion(lhs) == quaternion(rhs)` is false. As with any floating-type entity, this is essentially meaningless. [h4 Stream Extractor] template ::std::basic_istream& operator >> (::std::basic_istream & is, quaternion & q); Extracts a quaternion q of one of the following forms (with a, b, c and d of type `T`): [^a (a), (a,b), (a,b,c), (a,b,c,d) (a,(c)), (a,(c,d)), ((a)), ((a),c), ((a),(c)), ((a),(c,d)), ((a,b)), ((a,b),c), ((a,b),(c)), ((a,b),(c,d))] The input values must be convertible to `T`. If bad input is encountered, calls `is.setstate(ios::failbit)` (which may throw ios::failure (27.4.5.3)). [*Returns:] `is`. The rationale for the list of accepted formats is that either we have a list of up to four reals, or else we have a couple of complex numbers, and in that case if it formated as a proper complex number, then it should be accepted. Thus potential ambiguities are lifted (for instance (a,b) is (a,b,0,0) and not (a,0,b,0), i.e. it is parsed as a list of two real numbers and not two complex numbers which happen to have imaginary parts equal to zero). [h4 Stream Inserter] template ::std::basic_ostream& operator << (::std::basic_ostream & os, quaternion const & q); Inserts the quaternion q onto the stream `os` as if it were implemented as follows: template ::std::basic_ostream& operator << ( ::std::basic_ostream & os, quaternion const & q) { ::std::basic_ostringstream s; s.flags(os.flags()); s.imbue(os.getloc()); s.precision(os.precision()); s << '(' << q.R_component_1() << ',' << q.R_component_2() << ',' << q.R_component_3() << ',' << q.R_component_4() << ')'; return os << s.str(); } [endsect] [section Quaternion Value Operations] [h4 real and unreal] template T real(quaternion const & q); template quaternion unreal(quaternion const & q); These return `q.real()` and `q.unreal()` respectively. [h4 conj] template quaternion conj(quaternion const & q); This returns the conjugate of the quaternion. [h4 sup] template T sup(quaternion const & q); This return the sup norm (the greatest among `abs(q.R_component_1())...abs(q.R_component_4()))` of the quaternion. [h4 l1] template T l1(quaternion const & q); This return the l1 norm `(abs(q.R_component_1())+...+abs(q.R_component_4()))` of the quaternion. [h4 abs] template T abs(quaternion const & q); This return the magnitude (Euclidian norm) of the quaternion. [h4 norm] template T norm(quaternionconst & q); This return the (Cayley) norm of the quaternion. The term "norm" might be confusing, as most people associate it with the Euclidian norm (and quadratic functionals). For this version of (the mathematical objects known as) quaternions, the Euclidian norm (also known as magnitude) is the square root of the Cayley norm. [endsect] [section Quaternion Creation Functions] template quaternion spherical(T const & rho, T const & theta, T const & phi1, T const & phi2); template quaternion semipolar(T const & rho, T const & alpha, T const & theta1, T const & theta2); template quaternion multipolar(T const & rho1, T const & theta1, T const & rho2, T const & theta2); template quaternion cylindrospherical(T const & t, T const & radius, T const & longitude, T const & latitude); template quaternion cylindrical(T const & r, T const & angle, T const & h1, T const & h2); These build quaternions in a way similar to the way polar builds complex numbers, as there is no strict equivalent to polar coordinates for quaternions. [#boost_math.quaternions.creation_spherical] `spherical` is a simple transposition of `polar`, it takes as inputs a (positive) magnitude and a point on the hypersphere, given by three angles. The first of these, `theta` has a natural range of `-pi` to `+pi`, and the other two have natural ranges of `-pi/2` to `+pi/2` (as is the case with the usual spherical coordinates in __R3). Due to the many symmetries and periodicities, nothing untoward happens if the magnitude is negative or the angles are outside their natural ranges. The expected degeneracies (a magnitude of zero ignores the angles settings...) do happen however. [#boost_math.quaternions.creation_cylindrical] `cylindrical` is likewise a simple transposition of the usual cylindrical coordinates in __R3, which in turn is another derivative of planar polar coordinates. The first two inputs are the polar coordinates of the first __C component of the quaternion. The third and fourth inputs are placed into the third and fourth __R components of the quaternion, respectively. [#boost_math.quaternions.creation_multipolar] `multipolar` is yet another simple generalization of polar coordinates. This time, both __C components of the quaternion are given in polar coordinates. [#boost_math.quaternions.creation_cylindrospherical] `cylindrospherical` is specific to quaternions. It is often interesting to consider __H as the cartesian product of __R by __R3 (the quaternionic multiplication as then a special form, as given here). This function therefore builds a quaternion from this representation, with the __R3 component given in usual __R3 spherical coordinates. [#boost_math.quaternions.creation_semipolar] `semipolar` is another generator which is specific to quaternions. It takes as a first input the magnitude of the quaternion, as a second input an angle in the range `0` to `+pi/2` such that magnitudes of the first two __C components of the quaternion are the product of the first input and the sine and cosine of this angle, respectively, and finally as third and fourth inputs angles in the range `-pi/2` to `+pi/2` which represent the arguments of the first and second __C components of the quaternion, respectively. As usual, nothing untoward happens if what should be magnitudes are negative numbers or angles are out of their natural ranges, as symmetries and periodicities kick in. In this version of our implementation of quaternions, there is no analogue of the complex value operation `arg` as the situation is somewhat more complicated. Unit quaternions are linked both to rotations in __R3 and in __R4, and the correspondences are not too complicated, but there is currently a lack of standard (de facto or de jure) matrix library with which the conversions could work. This should be remedied in a further revision. In the mean time, an example of how this could be done is presented here for [@../../libs/math/quaternion/HSO3.hpp __R3], and here for [@../../libs/math/quaternion/HSO4.hpp __R4] ([@../../libs/math/quaternion/HSO3SO4.cpp example test file]). [endsect] [section Quaternion Transcendentals] There is no `log` or `sqrt` provided for quaternions in this implementation, and `pow` is likewise restricted to integral powers of the exponent. There are several reasons to this: on the one hand, the equivalent of analytic continuation for quaternions ("branch cuts") remains to be investigated thoroughly (by me, at any rate...), and we wish to avoid the nonsense introduced in the standard by exponentiations of complexes by complexes (which is well defined, but not in the standard...). Talking of nonsense, saying that `pow(0,0)` is "implementation defined" is just plain brain-dead... We do, however provide several transcendentals, chief among which is the exponential. This author claims the complete proof of the "closed formula" as his own, as well as its independant invention (there are claims to prior invention of the formula, such as one by Professor Shoemake, and it is possible that the formula had been known a couple of centuries back, but in absence of bibliographical reference, the matter is pending, awaiting further investigation; on the other hand, the definition and existence of the exponential on the quaternions, is of course a fact known for a very long time). Basically, any converging power series with real coefficients which allows for a closed formula in __C can be transposed to __H. More transcendentals of this type could be added in a further revision upon request. It should be noted that it is these functions which force the dependency upon the [@../../boost/math/special_functions/sinc.hpp boost/math/special_functions/sinc.hpp] and the [@../../boost/math/special_functions/sinhc.hpp boost/math/special_functions/sinhc.hpp] headers. [h4 exp] template quaternion exp(quaternion const & q); Computes the exponential of the quaternion. [h4 cos] template quaternion cos(quaternion const & q); Computes the cosine of the quaternion [h4 sin] template quaternion sin(quaternion const & q); Computes the sine of the quaternion. [h4 tan] template quaternion tan(quaternion const & q); Computes the tangent of the quaternion. [h4 cosh] template quaternion cosh(quaternion const & q); Computes the hyperbolic cosine of the quaternion. [h4 sinh] template quaternion sinh(quaternion const & q); Computes the hyperbolic sine of the quaternion. [h4 tanh] template quaternion tanh(quaternion const & q); Computes the hyperbolic tangent of the quaternion. [h4 pow] template quaternion pow(quaternion const & q, int n); Computes the n-th power of the quaternion q. [endsect] [section Test Program] The [@../../libs/math/quaternion/quaternion_test.cpp quaternion_test.cpp] test program tests quaternions specializations for float, double and long double ([@../../libs/math/quaternion/output.txt sample output], with message output enabled). If you define the symbol BOOST_QUATERNION_TEST_VERBOSE, you will get additional output ([@../../libs/math/quaternion/output_more.txt verbose output]); this will only be helpfull if you enable message output at the same time, of course (by uncommenting the relevant line in the test or by adding [^--log_level=messages] to your command line,...). In that case, and if you are running interactively, you may in addition define the symbol BOOST_INTERACTIVE_TEST_INPUT_ITERATOR to interactively test the input operator with input of your choice from the standard input (instead of hard-coding it in the test). [endsect] [section Acknowledgements] The mathematical text has been typeset with [@http://www.nisus-soft.com/ Nisus Writer]. Jens Maurer has helped with portability and standard adherence, and was the Review Manager for this library. More acknowledgements in the History section. Thank you to all who contributed to the discution about this library. [endsect] [section History] * 1.5.8 - 17/12/2005: Converted documentation to Quickbook Format. * 1.5.7 - 24/02/2003: transitionned to the unit test framework; now included by the library header (rather than the test files). * 1.5.6 - 15/10/2002: Gcc2.95.x and stlport on linux compatibility by Alkis Evlogimenos (alkis@routescience.com). * 1.5.5 - 27/09/2002: Microsoft VCPP 7 compatibility, by Michael Stevens (michael@acfr.usyd.edu.au); requires the /Za compiler option. * 1.5.4 - 19/09/2002: fixed problem with multiple inclusion (in different translation units); attempt at an improved compatibility with Microsoft compilers, by Michael Stevens (michael@acfr.usyd.edu.au) and Fredrik Blomqvist; other compatibility fixes. * 1.5.3 - 01/02/2002: bugfix and Gcc 2.95.3 compatibility by Douglas Gregor (gregod@cs.rpi.edu). * 1.5.2 - 07/07/2001: introduced namespace math. * 1.5.1 - 07/06/2001: (end of Boost review) now includes and instead of ; corrected bug in sin (Daryle Walker); removed check for self-assignment (Gary Powel); made converting functions explicit (Gary Powel); added overflow guards for division operators and abs (Peter Schmitteckert); added sup and l1; used Vesa Karvonen's CPP metaprograming technique to simplify code. * 1.5.0 - 26/03/2001: boostification, inlining of all operators except input, output and pow, fixed exception safety of some members (template version) and output operator, added spherical, semipolar, multipolar, cylindrospherical and cylindrical. * 1.4.0 - 09/01/2001: added tan and tanh. * 1.3.1 - 08/01/2001: cosmetic fixes. * 1.3.0 - 12/07/2000: pow now uses Maarten Hilferink's (mhilferink@tip.nl) algorithm. * 1.2.0 - 25/05/2000: fixed the division operators and output; changed many signatures. * 1.1.0 - 23/05/2000: changed sinc into sinc_pi; added sin, cos, sinh, cosh. * 1.0.0 - 10/08/1999: first public version. [endsect] [section To Do] * Improve testing. * Rewrite input operatore using Spirit (creates a dependency). * Put in place an Expression Template mechanism (perhaps borrowing from uBlas). * Use uBlas for the link with rotations (and move from the [@../../libs/math/quaternion/HSO3SO4.cpp example] implementation to an efficient one). [endsect] [endsect]