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Isis 3.0 Developer's Reference (API)

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Isis::Quaternion Class Reference

Provide operations for quaternion arithmetic. More...

#include <Quaternion.h>

List of all members.

Public Member Functions

 Quaternion ()
 Constructs an empty quaternion.
 Quaternion (const std::vector< double > matrix)
 Construct a Quaternion class from a matrix stored as a vector < double > with 9 elements or from a quaternion stored as a vector < double > with 4 elements.
 ~Quaternion ()
 Destroys the Quaternion object.
std::vector< double > ToMatrix ()
 Converts quaternion to 3x3 rotational matrix.
std::vector< double > ToAngles (int axis3, int axis2, int axis1)
 Return the camera angles (right ascension, declination, and twist) for the quaternion.
void Set (std::vector< double >)
 Sets the quaternion value.
std::vector< double > GetQuaternion () const
 Return the quaternion as a vector.
Quaternion & operator= (const Quaternion &quat)
 Assign value of quaternion class to another quaternion.
Quaternion & operator*= (const Quaternion &quat)
 Multiply current Naif quaternion by another Naif quaternion, replacing the current quaternion.
Quaternion operator* (const Quaternion &quat) const
 Multiply two Naif quaternions to create a new quaternion.
Quaternion operator* (const double &scalar)
 Multiply a quaternion by a scalar.
double & operator[] (int index)
 Return a member of a quaternion.
std::vector< double > Qxv (const std::vector< double > &vin)
 Multiply a vector by a quaternion (rotate the vector).
Quaternion Conjugate ()
 Returns the conjugate of the quaternion.

Detailed Description

Provide operations for quaternion arithmetic.

This class provides a wrapper for existing Naif quaternion functions and also includes other operators and methods useful for working with quaternions.

Author:
2005-12-07 Debbie A. Cook

Constructor & Destructor Documentation

Isis::Quaternion::Quaternion (  ) 

Constructs an empty quaternion.

Isis::Quaternion::Quaternion ( const std::vector< double >  rotation  ) 

Construct a Quaternion class from a matrix stored as a vector < double > with 9 elements or from a quaternion stored as a vector < double > with 4 elements.

Parameters:
rotation rotation defined as either a matrix or another quaternion loaded as a vector

References Set().

Isis::Quaternion::~Quaternion (  ) 

Destroys the Quaternion object.

Member Function Documentation

Quaternion Isis::Quaternion::Conjugate (  ) 

Returns the conjugate of the quaternion.

Referenced by Qxv().

std::vector<double> Isis::Quaternion::GetQuaternion (  )  const [inline]

Return the quaternion as a vector.

Quaternion Isis::Quaternion::operator* ( const double &  scalar  ) 

Multiply a quaternion by a scalar.

Just multiply the rotation part and polish the resulting quaternion so it is still a unit quaternion with positive rotation. For example, 

  Quaternion q1(),q(2);
  double scalar
  ...
  q2() = scalar*q2;
Parameters:
[in] scalar (const double &) scalar value to be multiplied times the current quaternion
Returns:
(Quaternion) product of scalar and quaternion

References _FILEINFO_, and Isis::IException::Programmer.

Quaternion Isis::Quaternion::operator* ( const Quaternion &  quat  )  const

Multiply two Naif quaternions to create a new quaternion.

For example, 

  Quaternion q1(),q(2);
  ...
  Quaternion q3() = q1*q2;

More information is available on quaternions and the multiplication algorithm in the Naif routine qxq_c.c

Parameters:
[in] quat (const Quaternion &) quaternion to multiply on the right
Returns:
(Quaternion) product of quaternions
Quaternion & Isis::Quaternion::operator*= ( const Quaternion &  quat  ) 

Multiply current Naif quaternion by another Naif quaternion, replacing the current quaternion.

For example, 

  Quaternion q1(),q(2);
  ...
  Quaternion q2() *= q1;

More information on quaternions and the multiplication algorithm is available in the Naif routine qxq_c.

Parameters:
[in] quat (const Quaternion &) quaternion to multiply on the right
Returns:
(Quaternion) product of quaternions
Quaternion & Isis::Quaternion::operator= ( const Quaternion &  quat  ) 

Assign value of quaternion class to another quaternion.

For example, 

  Quaternion q1( matrix );
  Quaternion q2();
  ...
  q2 = q1;
Parameters:
quat The Quaternion to copy
double& Isis::Quaternion::operator[] ( int  index  )  [inline]

Return a member of a quaternion.

For example, 

  Quaternion q();
 ...
  double angle = q[0];
Parameters:
[in] index (const int &) quaternion member to return
Returns:
(double&) value pointed to by iter
std::vector< double > Isis::Quaternion::Qxv ( const std::vector< double > &  vin  ) 

Multiply a vector by a quaternion (rotate the vector).

Parameters:
[in] vin (const std::vector<double>(3)) Vector to be multiplied (rotated)

References _FILEINFO_, Conjugate(), and Isis::IException::Programmer.

void Isis::Quaternion::Set ( std::vector< double >  rotation  ) 

Sets the quaternion value.

Parameters:
rotation rotation defined as either a matrix or a set of 3 angles

References _FILEINFO_, and Isis::IException::Programmer.

Referenced by Quaternion().

std::vector< double > Isis::Quaternion::ToAngles ( int  axis3,
int  axis2,
int  axis1 
)

Return the camera angles (right ascension, declination, and twist) for the quaternion.

References ToMatrix().

std::vector< double > Isis::Quaternion::ToMatrix (  ) 

Converts quaternion to 3x3 rotational matrix.

Referenced by ToAngles().

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