Class defining a direction cosine matrix inherited from Matrix. More...

#include <DCM.hpp>

Inheritance diagram for clockwerk::DCM< T >:

Collaboration diagram for clockwerk::DCM< T >:

Public Member Functions
	DCM ()
	Default constructor generates DCM as an identity matrix.

	DCM (const T(&initial)[3][3])
	Constructor for Matrix class with initialization. Initializes matrix to values passed in via array.

	DCM (const DCM< T > &initial)
	Copy constructor for Matrix class. Copies data from matrix object to the current instance.

	DCM (const std::array< std::array< T, 3 >, 3 > &initial)
	Constructor for Matrix class with initialization. Initializes matrix to values passed in via array.

	~DCM ()
	Destructor – doesn't do anything because we don't dynamically allocate.

int	inverse (DCM< T > &result) const
	Function to return the inverse of the matrix.

DCM< T >	inverse () const

void	rate (const CartesianVector< T, 3 > &omega_f1_f2__f1, Matrix< T, 3, 3 > &dcmdot_f1_f2)
	Function to calculate the rate of change in the current representation based on the omega vector.

int	toEuler321 (Euler321< T > &euler_f1_f2) const
	Function to convert current attitude to 321 Euler sequence.

Euler321< T >	toEuler321 ()

int	toQuaternion (Quaternion< T > &q_f1_f2) const
	Overloaded functions to convert current attitude to quaternion.

Quaternion< T >	toQuaternion ()

int	toMRP (MRP< T > &mrp_f1_f2) const
	Overloaded functions to convert current attitude to MRP.

MRP< T >	toMRP ()

void	dump () const
	Function to dump information on matrix.

std::string	str () const
	Function to dump information on matrix to string.

int	set (const unsigned int &row, const unsigned int &col, const T &value)
	Function to set a single value in the matrix.

int	get (const unsigned int &row, const unsigned int &col, T &result) const
	Function to get a single value in the matrix.

T	get (const unsigned int &row, const unsigned int &col) const
	Function to get a single value in the matrix.

void	setFromArray (const T *start_ptr)
	Function to set the values of the matrix row-wise.

void	getAsArray (T *start_ptr) const
	Function to get the values of the matrix row-wise.

void	getCopy (Matrix< T, R, C > &result) const
	Function to get a copy of the matrix.

T *	operator[] (unsigned int idx)
	Function to return a matrix row or vector value.

std::pair< unsigned int, unsigned int >	size ()
	Function to get the size of the matrix.

void	max (T &result, std::pair< unsigned int, unsigned int > &index) const
	Function to return the maximum value in the matrix.

void	min (T &result, std::pair< unsigned int, unsigned int > &index) const
	Function to return the minimum value in the matrix.

int	det (T &result) const
	Function to return the determinant of the matrix.

int	inverse (Matrix< T, R, C > &result) const
	Function to return the inverse of the matrix.

void	transpose (Matrix< T, C, R > &result) const
	Function to return the transpose of the matrix.

Matrix< T, C, R >	transpose () const

int	trace (T &result) const
	Function to return the trace of the matrix.

void	setToZeros ()
	Function to set all elements of the matrix to zero.

int	identity ()
	Function to set matrix to identity, if it is a square matrix.

int	eye ()

Public Attributes
std::array< std::array< T, C >, R >	values
	The actual values held by the matrix – a two dimensional array of values indexed as (row, column). NOTE: Public for ease of access and speed (no need to use setter/getter), and functions in Matrix and Safemath libraries are tested safe. Behavior using matrices outside of clockwerk libraries should use setter/getter, rather than direct access, for safety.

Protected Member Functions
int	_checkLookupBoundaries (const unsigned int &start_r, const unsigned int &end_r, const unsigned int &start_c, const unsigned int &end_c) const
	Function to check, given a set of submatrix boundaries, that those boundaries are valid for the current matrix.

int	_LUPDecompose (T *A[R], unsigned int P[R+1]) const
	Function to take a 2-d matrix represented by A and decompose it into LU form.

Detailed Description

template<typename T>
class clockwerk::DCM< T >

Class defining a direction cosine matrix inherited from Matrix.

This file defines a simple DCM attitude representation for cartesian coordinate systems. It is largely the same as the base matrix class, with the following exceptions:

Set to be square, 3x3 (that's where it will primarily be used)
Default constructor is identity matrix, rather than zeroes
Inverse is set to account for orthogonal matrix
Functions defined to convert to other attitude
Function defined to calculate rate of change as a function of omega

Naming conventions

All naming conventions and equations are per Analytical Mechanics of Space Systems by Schaub and Junkins
The omega vector is sometimes denoted by w and assumed frame consistent with the attitude representation. For example, if a DCM represents the relative orientation between two frames [BN] the omega vector is assumed to be w_(B/N)
The naming convention for all vectors is: variablename_obj1_obj2__frameN (note the double underscore preceding frame) and reads back as: "variable variablename representing the relationship between obj1 and obj2 represented in frameN"
Unless otherwise noted angles are in RADIANS NOTE: All attitude representations, including DCMs, are assumed to represent a three dimensional, cartesian coordinate system because that is what they are used, and in many cases defined, for.

Member Function Documentation

◆ _LUPDecompose()

int clockwerk::Matrix< T, R, C >::_LUPDecompose	(	T *	A[R],
		unsigned int	P[R+1]
	)		const

protectedinherited

Function to take a 2-d matrix represented by A and decompose it into LU form.

Parameters

A	A 2-d matrix represented as a double pointer After ops A contains a copy of both matrices L-E and U as A=(L-E)+U such that PA=LU.
P	The permutation matrix to hold info on matrix changes

Returns: Error code corresponding to codes in clockwerkerrors.h

Note: Code borrowed/updated from sample C code on wikipedia here: https://en.wikipedia.org/wiki/LU_decomposition

◆ det()

int clockwerk::Matrix< T, R, C >::det ( T & result ) const

inherited

Function to return the determinant of the matrix.

Operations to return important matrix information

Returns: Integer value corresponding to error codes in clockwerkerrrors.h

◆ get() [1/2]

T clockwerk::Matrix< T, R, C >::get	(	const unsigned int &	row,
		const unsigned int &	col
	)		const

inherited

Function to get a single value in the matrix.

Parameters

row	The row index
col	The column index

Returns: Matrix value at index

Note: Does not bounds check and is unsafe for embedded operations

◆ get() [2/2]

int clockwerk::Matrix< T, R, C >::get	(	const unsigned int &	row,
		const unsigned int &	col,
		T &	result
	)		const

inherited

Function to get a single value in the matrix.

Parameters

row	The row index
col	The column index
value	PBR return of the value in the matrix

Returns: Integer value corresponding to error codes in clockwerkerrrors.h

◆ getAsArray()

void clockwerk::Matrix< T, R, C >::getAsArray ( T * start_ptr ) const

inherited

Function to get the values of the matrix row-wise.

Parameters

start_ptr The data address at which write should begin.

Note: start_ptr must represent an array or similar type of at least R*C values; Not protected. May segfault if not used properly; The matrix [1 2; 3 4] would output as an array [1 2 3 4]

◆ getCopy()

void clockwerk::Matrix< T, R, C >::getCopy ( Matrix< T, R, C > & result ) const

inherited

Function to get a copy of the matrix.

Parameters

result PBR return of a copy of this matrix

◆ identity()

int clockwerk::Matrix< T, R, C >::identity ( )

inherited

Function to set matrix to identity, if it is a square matrix.

Returns: Error code corresponding to success/failure

◆ inverse() [1/2]

template<typename T >

int clockwerk::DCM< T >::inverse ( DCM< T > & result ) const

Function to return the inverse of the matrix.

Parameters

result PBR return of matrix inverse

Returns: Integer value corresponding to error codes in clockwerkerrrors.h

Note: Overloaded for value return

◆ inverse() [2/2]

int clockwerk::Matrix< T, R, C >::inverse ( Matrix< T, R, C > & result ) const

inherited

Function to return the inverse of the matrix.

Parameters

result PBR return of matrix inverse

Returns: Integer value corresponding to error codes in clockwerkerrrors.h

◆ max()

void clockwerk::Matrix< T, R, C >::max	(	T &	result,
		std::pair< unsigned int, unsigned int > &	index
	)		const

inherited

Function to return the maximum value in the matrix.

Parameters

result PBR return of maximum value

◆ min()

void clockwerk::Matrix< T, R, C >::min	(	T &	result,
		std::pair< unsigned int, unsigned int > &	index
	)		const

inherited

Function to return the minimum value in the matrix.

Parameters

result PBR return of minimum value

◆ operator[]()

T * clockwerk::Matrix< T, R, C >::operator[] ( unsigned int idx )

inherited

Function to return a matrix row or vector value.

Parameters

idx	The row index to return

Returns: A pointer to the row element of the matrix. Nullptr if out of range

◆ rate()

template<typename T >

void clockwerk::DCM< T >::rate	(	const CartesianVector< T, 3 > &	omega_f1_f2__f1,
		Matrix< T, 3, 3 > &	dcmdot_f1_f2
	)

Function to calculate the rate of change in the current representation based on the omega vector.

Dynamics and kinematics functions

Parameters

omega_f1_f2__f1	Angular velocity vector for the attitude representation - omega of frame 1 wrt frame 2 expressed in frame 1
dcmdot_f1_f2	Rate of change in the current DCM

◆ set()

int clockwerk::Matrix< T, R, C >::set	(	const unsigned int &	row,
		const unsigned int &	col,
		const T &	value
	)

inherited

Function to set a single value in the matrix.

Getters and setters

Parameters

row	The row index
col	The column index
value	The value to set the matrix to

Returns: Integer value corresponding to error codes in clockwerkerrrors.h

◆ setFromArray()

void clockwerk::Matrix< T, R, C >::setFromArray ( const T * start_ptr )

inherited

Function to set the values of the matrix row-wise.

Parameters

start_ptr The data address at which read should begin.

Note: start_ptr must represent an array or similar type of at least R*C values; Not protected. May segfault if not used properly; The array [1 2 3 4] would read into a matrix as [1 2; 3 4]

◆ size()

std::pair< unsigned int, unsigned int > clockwerk::Matrix< T, R, C >::size ( )

inlineinherited

Function to get the size of the matrix.

Operations to get matrix info

◆ toEuler321()

template<typename T >

int clockwerk::DCM< T >::toEuler321 ( Euler321< T > & euler_f1_f2 ) const

Function to convert current attitude to 321 Euler sequence.

Conversions to other attitude representations

Parameters

PBR	return of 321 Euler sequence in PBR case

Returns: Integer error code corresponding to errors in clockwerkerrors.h

Note: Cannot overload for return by value because conversion isn't guaranteed

◆ toMRP()

template<typename T >

int clockwerk::DCM< T >::toMRP ( MRP< T > & mrp_f1_f2 ) const

Overloaded functions to convert current attitude to MRP.

Parameters

PBR	return of MRP in PBR case

Returns: MRP in return by value case

◆ toQuaternion()

template<typename T >

int clockwerk::DCM< T >::toQuaternion ( Quaternion< T > & q_f1_f2 ) const

Overloaded functions to convert current attitude to quaternion.

Parameters

PBR	return of quaternion in PBR case

Returns: Quaternion in return by value case

◆ trace()

int clockwerk::Matrix< T, R, C >::trace ( T & result ) const

inherited

Function to return the trace of the matrix.

Parameters

result PBR return of matrix trace

Returns: Integer value corresponding to error codes in clockwerkerrrors.h

◆ transpose()

void clockwerk::Matrix< T, R, C >::transpose ( Matrix< T, C, R > & result ) const

inherited

Function to return the transpose of the matrix.

Parameters

result PBR return of matrix transpose

Note: Overloaded for return as well

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

/home/mickey/modelspace/clockwerk/src/six_dof_dynamics/DCM.hpp

Public Member Functions

Public Attributes

Protected Member Functions

Detailed Description

Naming conventions

Member Function Documentation

◆ _LUPDecompose()

◆ det()

Operations to return important matrix information

◆ get() [1/2]

◆ get() [2/2]

◆ getAsArray()

◆ getCopy()

◆ identity()

◆ inverse() [1/2]

◆ inverse() [2/2]

◆ max()

◆ min()

◆ operator[]()

◆ rate()

Dynamics and kinematics functions

◆ set()

Getters and setters

◆ setFromArray()

◆ size()

Operations to get matrix info

◆ toEuler321()

Conversions to other attitude representations

◆ toMRP()

◆ toQuaternion()

◆ trace()

◆ transpose()