Eigen::AngleAxis< Scalar_ > Class Template Reference

Represents a 3D rotation as a rotation angle around an arbitrary 3D axis. More...

Inheritance diagram for Eigen::AngleAxis< Scalar_ >:

Public Types
enum	{ Dim }
typedef Matrix< Scalar, 3, 3 >	Matrix3
typedef Quaternion< Scalar >	QuaternionType
typedef Scalar_	Scalar
typedef Matrix< Scalar, 3, 1 >	Vector3
Public Types inherited from Eigen::RotationBase< AngleAxis< Scalar_ >, 3 >
enum
typedef Matrix< Scalar, Dim, Dim >	RotationMatrixType
typedef internal::traits< AngleAxis< Scalar_ > >::Scalar	Scalar
typedef Matrix< Scalar, Dim, 1 >	VectorType

Public Member Functions
Scalar &	angle ()
Scalar	angle () const
	AngleAxis ()
template<typename OtherScalarType >
	AngleAxis (const AngleAxis< OtherScalarType > &other)
template<typename Derived >
	AngleAxis (const MatrixBase< Derived > &m)
template<typename QuatDerived >
	AngleAxis (const QuaternionBase< QuatDerived > &q)
template<typename Derived >
	AngleAxis (const Scalar &angle, const MatrixBase< Derived > &axis)
Vector3 &	axis ()
const Vector3 &	axis () const
template<typename NewScalarType >
internal::cast_return_type< AngleAxis, AngleAxis< NewScalarType > >::type	cast () const
template<typename Derived >
AngleAxis &	fromRotationMatrix (const MatrixBase< Derived > &m)
template<typename Derived >
AngleAxis< Scalar > &	fromRotationMatrix (const MatrixBase< Derived > &mat)
	Sets *this from a 3x3 rotation matrix. More...
AngleAxis	inverse () const
bool	isApprox (const AngleAxis &other, const typename NumTraits< Scalar >::Real &prec=NumTraits< Scalar >::dummy_precision()) const
QuaternionType	operator* (const AngleAxis &other) const
QuaternionType	operator* (const QuaternionType &other) const
template<typename Derived >
AngleAxis &	operator= (const MatrixBase< Derived > &m)
template<typename Derived >
AngleAxis< Scalar > &	operator= (const MatrixBase< Derived > &mat)
template<class QuatDerived >
AngleAxis &	operator= (const QuaternionBase< QuatDerived > &q)
template<typename QuatDerived >
AngleAxis< Scalar > &	operator= (const QuaternionBase< QuatDerived > &q)
Matrix3	toRotationMatrix (void) const
Public Member Functions inherited from Eigen::RotationBase< AngleAxis< Scalar_ >, 3 >
VectorType	_transformVector (const OtherVectorType &v) const
AngleAxis< Scalar_ > &	derived ()
const AngleAxis< Scalar_ > &	derived () const
AngleAxis< Scalar_ >	inverse () const
RotationMatrixType	matrix () const
internal::rotation_base_generic_product_selector< AngleAxis< Scalar_ >, OtherDerived, OtherDerived::IsVectorAtCompileTime >::ReturnType	operator* (const EigenBase< OtherDerived > &e) const
Transform< Scalar, Dim, Mode >	operator* (const Transform< Scalar, Dim, Mode, Options > &t) const
Transform< Scalar, Dim, Isometry >	operator* (const Translation< Scalar, Dim > &t) const
RotationMatrixType	operator* (const UniformScaling< Scalar > &s) const
RotationMatrixType	toRotationMatrix () const

Static Public Member Functions
static const AngleAxis	Identity ()

Protected Attributes
Scalar	m_angle
Vector3	m_axis

Private Types
typedef RotationBase< AngleAxis< Scalar_ >, 3 >	Base

Detailed Description

template<typename Scalar_>
class Eigen::AngleAxis< Scalar_ >

Represents a 3D rotation as a rotation angle around an arbitrary 3D axis.

This is defined in the Geometry module.

#include <Eigen/Geometry> 

Code

Parameters

Scalar_

the scalar type, i.e., the type of the coefficients.

Warning

When setting up an AngleAxis object, the axis vector must be normalized.

The following two typedefs are provided for convenience:

• AngleAxisf for float
• AngleAxisd for double

Combined with MatrixBase::Unit{X,Y,Z}, AngleAxis can be used to easily mimic Euler-angles. Here is an example:

Matrix3f m;
m = AngleAxisf(0.25*M_PI, Vector3f::UnitX())
  * AngleAxisf(0.5*M_PI,  Vector3f::UnitY())
  * AngleAxisf(0.33*M_PI, Vector3f::UnitZ());
cout << m << endl << "is unitary: " << m.isUnitary() << endl;

Code

Output:

1.19e-07        0        1
   0.969   -0.249        0
   0.249    0.969 1.19e-07
is unitary: 1

Code

Note

This class is not aimed to be used to store a rotation transformation, but rather to make easier the creation of other rotation (Quaternion, rotation Matrix) and transformation objects.

See also

class Quaternion, class Transform, MatrixBase::UnitX()

Definition at line 51 of file AngleAxis.h.

Member Typedef Documentation

Base

template<typename Scalar_ >

typedef RotationBase<AngleAxis<Scalar_>,3> Eigen::AngleAxis< Scalar_ >::Base

private

Definition at line 53 of file AngleAxis.h.

Matrix3

template<typename Scalar_ >

typedef Matrix<Scalar,3,3> Eigen::AngleAxis< Scalar_ >::Matrix3

Definition at line 62 of file AngleAxis.h.

QuaternionType

template<typename Scalar_ >

typedef Quaternion<Scalar> Eigen::AngleAxis< Scalar_ >::QuaternionType

Definition at line 64 of file AngleAxis.h.

Scalar

template<typename Scalar_ >

typedef Scalar_ Eigen::AngleAxis< Scalar_ >::Scalar

the scalar type of the coefficients

Definition at line 61 of file AngleAxis.h.

Vector3

template<typename Scalar_ >

typedef Matrix<Scalar,3,1> Eigen::AngleAxis< Scalar_ >::Vector3

Definition at line 63 of file AngleAxis.h.

Member Enumeration Documentation

anonymous enum

template<typename Scalar_ >

anonymous enum

Enumerator
Dim

Definition at line 59 of file AngleAxis.h.

{ Dim = 3 };

Code

Constructor & Destructor Documentation

AngleAxis() [1/5]

template<typename Scalar_ >

Eigen::AngleAxis< Scalar_ >::AngleAxis ( )

inline

Default constructor without initialization.

Definition at line 74 of file AngleAxis.h.

{}

Code

AngleAxis() [2/5]

template<typename Scalar_ >

template<typename Derived >

Eigen::AngleAxis< Scalar_ >::AngleAxis ( const Scalar &  angle, const MatrixBase< Derived > &  axis  )

inline

Constructs and initialize the angle-axis rotation from an angle in radian and an axis which must be normalized.

Warning

If the axis vector is not normalized, then the angle-axis object represents an invalid rotation.

Definition at line 82 of file AngleAxis.h.

: m_axis(axis), m_angle(angle) {}

Code

AngleAxis() [3/5]

template<typename Scalar_ >

template<typename QuatDerived >

Eigen::AngleAxis< Scalar_ >::AngleAxis ( const QuaternionBase< QuatDerived > &  q )

inlineexplicit

Constructs and initialize the angle-axis rotation from a quaternion q. This function implicitly normalizes the quaternion q.

Definition at line 87 of file AngleAxis.h.

{ *this = q; }

Code

AngleAxis() [4/5]

template<typename Scalar_ >

template<typename Derived >

Eigen::AngleAxis< Scalar_ >::AngleAxis ( const MatrixBase< Derived > &  m )

inlineexplicit

Constructs and initialize the angle-axis rotation from a 3x3 rotation matrix.

Definition at line 90 of file AngleAxis.h.

{ *this = m; }

Code

AngleAxis() [5/5]

template<typename Scalar_ >

template<typename OtherScalarType >

Eigen::AngleAxis< Scalar_ >::AngleAxis ( const AngleAxis< OtherScalarType > &  other )

inlineexplicit

Copy constructor with scalar type conversion

Definition at line 141 of file AngleAxis.h.

  {
    m_axis = other.axis().template cast<Scalar>();
    m_angle = Scalar(other.angle());
  }

Code

Member Function Documentation

angle() [1/2]

template<typename Scalar_ >

Scalar& Eigen::AngleAxis< Scalar_ >::angle ( )

inline

Returns

a read-write reference to the stored angle in radian

Definition at line 95 of file AngleAxis.h.

{ return m_angle; }

Code

angle() [2/2]

template<typename Scalar_ >

Scalar Eigen::AngleAxis< Scalar_ >::angle ( ) const

inline

Returns

the value of the rotation angle in radian

Definition at line 93 of file AngleAxis.h.

{ return m_angle; }

Code

axis() [1/2]

template<typename Scalar_ >

Vector3& Eigen::AngleAxis< Scalar_ >::axis ( )

inline

Returns

a read-write reference to the stored rotation axis.

Warning

The rotation axis must remain a unit vector.

Definition at line 103 of file AngleAxis.h.

{ return m_axis; }

Code

axis() [2/2]

template<typename Scalar_ >

const Vector3& Eigen::AngleAxis< Scalar_ >::axis ( ) const

inline

Returns

the rotation axis

Definition at line 98 of file AngleAxis.h.

{ return m_axis; }

Code

cast()

template<typename Scalar_ >

template<typename NewScalarType >

internal::cast_return_type<AngleAxis,AngleAxis<NewScalarType> >::type Eigen::AngleAxis< Scalar_ >::cast ( ) const

inline

Returns

*this with scalar type casted to NewScalarType

Note that if NewScalarType is equal to the current scalar type of *this then this function smartly returns a const reference to *this.

Definition at line 136 of file AngleAxis.h.

  { return typename internal::cast_return_type<AngleAxis,AngleAxis<NewScalarType> >::type(*this); }

Code

fromRotationMatrix() [1/2]

template<typename Scalar_ >

template<typename Derived >

AngleAxis& Eigen::AngleAxis< Scalar_ >::fromRotationMatrix

(

const MatrixBase< Derived > &

m

)

fromRotationMatrix() [2/2]

template<typename Scalar_ >

template<typename Derived >

AngleAxis<Scalar>& Eigen::AngleAxis< Scalar_ >::fromRotationMatrix

(

const MatrixBase< Derived > &

mat

)

Sets *this from a 3x3 rotation matrix.

Definition at line 211 of file AngleAxis.h.

{
  return *this = QuaternionType(mat);
}

Code

Identity()

template<typename Scalar_ >

static const AngleAxis Eigen::AngleAxis< Scalar_ >::Identity ( )

inlinestatic

Definition at line 147 of file AngleAxis.h.

{ return AngleAxis(Scalar(0), Vector3::UnitX()); }

Code

inverse()

template<typename Scalar_ >

AngleAxis Eigen::AngleAxis< Scalar_ >::inverse ( ) const

inline

Returns

the inverse rotation, i.e., an angle-axis with opposite rotation angle

Definition at line 118 of file AngleAxis.h.

  { return AngleAxis(-m_angle, m_axis); }

Code

isApprox()

template<typename Scalar_ >

bool Eigen::AngleAxis< Scalar_ >::isApprox ( const AngleAxis< Scalar_ > &  other, const typename NumTraits< Scalar >::Real &  prec = NumTraits<Scalar>::dummy_precision()  ) const

inline

Returns

true if *this is approximately equal to other, within the precision determined by prec.

See also

MatrixBase::isApprox()

Definition at line 153 of file AngleAxis.h.

  { return m_axis.isApprox(other.m_axis, prec) && internal::isApprox(m_angle,other.m_angle, prec); }

Code

operator*() [1/2]

template<typename Scalar_ >

QuaternionType Eigen::AngleAxis< Scalar_ >::operator* ( const AngleAxis< Scalar_ > &  other ) const

inline

Concatenates two rotations

Definition at line 106 of file AngleAxis.h.

  { return QuaternionType(*this) * QuaternionType(other); }

Code

operator*() [2/2]

template<typename Scalar_ >

QuaternionType Eigen::AngleAxis< Scalar_ >::operator* ( const QuaternionType &  other ) const

inline

Concatenates two rotations

Definition at line 110 of file AngleAxis.h.

  { return QuaternionType(*this) * other; }

Code

operator=() [1/4]

template<typename Scalar_ >

template<typename Derived >

AngleAxis& Eigen::AngleAxis< Scalar_ >::operator=

(

const MatrixBase< Derived > &

m

)

operator=() [2/4]

template<typename Scalar_ >

template<typename Derived >

AngleAxis<Scalar>& Eigen::AngleAxis< Scalar_ >::operator=

(

const MatrixBase< Derived > &

mat

)

Set *this from a 3x3 rotation matrix mat.

Definition at line 199 of file AngleAxis.h.

{
  // Since a direct conversion would not be really faster,
  // let's use the robust Quaternion implementation:
  return *this = QuaternionType(mat);
}

Code

operator=() [3/4]

template<typename Scalar_ >

template<class QuatDerived >

AngleAxis& Eigen::AngleAxis< Scalar_ >::operator=

(

const QuaternionBase< QuatDerived > &

q

)

operator=() [4/4]

template<typename Scalar_ >

template<typename QuatDerived >

AngleAxis<Scalar>& Eigen::AngleAxis< Scalar_ >::operator=

(

const QuaternionBase< QuatDerived > &

q

)

Set *this from a unit quaternion.

The resulting axis is normalized, and the computed angle is in the [0,pi] range.

This function implicitly normalizes the quaternion q.

Definition at line 172 of file AngleAxis.h.

{
  EIGEN_USING_STD(atan2)
  EIGEN_USING_STD(abs)
  Scalar n = q.vec().norm();
  if(n<NumTraits<Scalar>::epsilon())
    n = q.vec().stableNorm();
 
  if (n != Scalar(0))
  {
    m_angle = Scalar(2)*atan2(n, abs(q.w()));
    if(q.w() < Scalar(0))
      n = -n;
    m_axis  = q.vec() / n;
  }
  else
  {
    m_angle = Scalar(0);
    m_axis << Scalar(1), Scalar(0), Scalar(0);
  }
  return *this;
}

Code

toRotationMatrix()

template<typename Scalar >

AngleAxis< Scalar >::Matrix3 Eigen::AngleAxis< Scalar >::toRotationMatrix

(

void

)

const

Constructs and

Returns

an equivalent 3x3 rotation matrix.

Definition at line 220 of file AngleAxis.h.

{
  EIGEN_USING_STD(sin)
  EIGEN_USING_STD(cos)
  Matrix3 res;
  Vector3 sin_axis  = sin(m_angle) * m_axis;
  Scalar c = cos(m_angle);
  Vector3 cos1_axis = (Scalar(1)-c) * m_axis;
 
  Scalar tmp;
  tmp = cos1_axis.x() * m_axis.y();
  res.coeffRef(0,1) = tmp - sin_axis.z();
  res.coeffRef(1,0) = tmp + sin_axis.z();
 
  tmp = cos1_axis.x() * m_axis.z();
  res.coeffRef(0,2) = tmp + sin_axis.y();
  res.coeffRef(2,0) = tmp - sin_axis.y();
 
  tmp = cos1_axis.y() * m_axis.z();
  res.coeffRef(1,2) = tmp - sin_axis.x();
  res.coeffRef(2,1) = tmp + sin_axis.x();
 
  res.diagonal() = (cos1_axis.cwiseProduct(m_axis)).array() + c;
 
  return res;
}

Code

Member Data Documentation

m_angle

template<typename Scalar_ >

Scalar Eigen::AngleAxis< Scalar_ >::m_angle

protected

Definition at line 69 of file AngleAxis.h.

m_axis

template<typename Scalar_ >

Vector3 Eigen::AngleAxis< Scalar_ >::m_axis

protected

Definition at line 68 of file AngleAxis.h.

---

The documentation for this class was generated from the following files:

• ForwardDeclarations.h
• AngleAxis.h