#include <visp3/core/vpVelocityTwistMatrix.h>

Inheritance diagram for vpVelocityTwistMatrix:

Public Member Functions
	vpVelocityTwistMatrix ()

	vpVelocityTwistMatrix (const vpVelocityTwistMatrix &V)

VP_EXPLICIT	vpVelocityTwistMatrix (const vpHomogeneousMatrix &M, bool full=true)

	vpVelocityTwistMatrix (const vpTranslationVector &t, const vpRotationMatrix &R)

	vpVelocityTwistMatrix (const vpTranslationVector &t, const vpThetaUVector &thetau)

	vpVelocityTwistMatrix (double tx, double ty, double tz, double tux, double tuy, double tuz)

VP_EXPLICIT	vpVelocityTwistMatrix (const vpRotationMatrix &R)

VP_EXPLICIT	vpVelocityTwistMatrix (const vpThetaUVector &thetau)

vpVelocityTwistMatrix &	buildFrom (const vpTranslationVector &t, const vpRotationMatrix &R)

vpVelocityTwistMatrix &	buildFrom (const vpTranslationVector &t, const vpThetaUVector &thetau)

vpVelocityTwistMatrix &	buildFrom (const vpHomogeneousMatrix &M, bool full=true)

vpVelocityTwistMatrix &	buildFrom (const vpRotationMatrix &R)

vpVelocityTwistMatrix &	buildFrom (const vpThetaUVector &thetau)

void	extract (vpRotationMatrix &R) const

void	extract (vpTranslationVector &t) const

void	eye ()

vpVelocityTwistMatrix	inverse () const

void	inverse (vpVelocityTwistMatrix &V) const

vpVelocityTwistMatrix	operator* (const vpVelocityTwistMatrix &V) const

vpMatrix	operator* (const vpMatrix &M) const

vpColVector	operator* (const vpColVector &v) const

vpVelocityTwistMatrix &	operator= (const vpVelocityTwistMatrix &V)

int	print (std::ostream &s, unsigned int length, char const *intro=0) const

void	resize (unsigned int nrows, unsigned int ncols, bool flagNullify=true)

Inherited functionalities from vpArray2D
unsigned int	getCols () const

double	getMaxValue () const

double	getMinValue () const

unsigned int	getRows () const

unsigned int	size () const

void	resize (unsigned int nrows, unsigned int ncols, bool flagNullify=true, bool recopy_=true)

void	reshape (unsigned int nrows, unsigned int ncols)

void	insert (const vpArray2D< double > &A, unsigned int r, unsigned int c)

bool	operator== (const vpArray2D< double > &A) const

bool	operator!= (const vpArray2D< double > &A) const

double *	operator[] (unsigned int i)

double *	operator[] (unsigned int i) const

vpArray2D< double >	hadamard (const vpArray2D< double > &m) const

vpArray2D< double >	t () const

Public Attributes
double *	data

Friends
class	vpMatrix

Related Functions
(Note that these are not member functions.)
enum	vpGEMMmethod

bool	operator== (const vpArray2D< double > &A) const

bool	operator== (const vpArray2D< float > &A) const

bool	operator!= (const vpArray2D< double > &A) const

void	vpGEMM (const vpArray2D< double > &A, const vpArray2D< double > &B, const double &alpha, const vpArray2D< double > &C, const double &beta, vpArray2D< double > &D, const unsigned int &ops=0)

Inherited I/O from vpArray2D with Static Public Member Functions
vpArray2D< double >	insert (const vpArray2D< double > &A, const vpArray2D< double > &B, unsigned int r, unsigned int c)

static void	insert (const vpArray2D< double > &A, const vpArray2D< double > &B, vpArray2D< double > &C, unsigned int r, unsigned int c)

unsigned int	rowNum

unsigned int	colNum

double **	rowPtrs

unsigned int	dsize

static bool	load (const std::string &filename, vpArray2D< double > &A, bool binary=false, char *header=nullptr)

static bool	loadYAML (const std::string &filename, vpArray2D< double > &A, char *header=nullptr)

static bool	save (const std::string &filename, const vpArray2D< double > &A, bool binary=false, const char *header="")

static bool	saveYAML (const std::string &filename, const vpArray2D< double > &A, const char *header="")

static vpArray2D< double >	conv2 (const vpArray2D< double > &M, const vpArray2D< double > &kernel, const std::string &mode)

static void	conv2 (const vpArray2D< double > &M, const vpArray2D< double > &kernel, vpArray2D< double > &res, const std::string &mode)

Detailed Description

This class derived from vpArray2D<double> implements the 6 by 6 matrix which transforms velocities from one frame to another. This matrix is also called velocity twist transformation matrix.

The full velocity twist transformation matrix allows to compute the velocity at point a expressed in frame a knowing its velocity at point b expressed in frame b. This matrix is defined as:

$^a{\bf V}_b = \left[\begin{array}{cc} ^a{\bf R}_b & [^a{\bf t}_b]_\times \; ^a{\bf R}_b\\ {\bf 0}_{3\times 3} & ^a{\bf R}_b \end{array} \right]$

where $^a{\bf R}_b$ is a rotation matrix and $^a{\bf t}_b$ is a translation vector.

There are different ways to initialize such a full velocity twist matrix. The following example shows how to proceed setting the translation and rotation matrix transformations:

#include <visp3/core/vpVelocityTwistMatrix.h>
 
#ifdef ENABLE_VISP_NAMESPACE
using namespace VISP_NAMESPACE_NAME;
#endif
 
int main()
{
  vpTranslationVector cte(0.1, 0.2, 0.3);
  vpRotationMatrix cRe( {0,  0, -1,
                        0, -1,  0,
                        -1,  0,  0} );
 
  vpVelocityTwistMatrix cVe(cte, cRe);
  std::cout << "cVe:\n" << cVe << std::endl;
}

It produces the following printings:

cVe:
0  -1  -0.2  0.3  0
-1  0  0.1  0  -0.3
-1  0  0  0  -0.1  0.2
0  0  0  0  -1
0  0  0  -1  0
0  0  -1  0  0

When the point where the velocity is expressed doesn't change, the matrix becomes block diagonal. It allows than to compute the velocity at point b expressed in frame a knowing its velocity at point b expressed in frame b :

$^a{\bf V}_b = \left[\begin{array}{cc} ^a{\bf R}_b & {\bf 0}_{3\times 3} \\ {\bf 0}_{3\times 3} & ^a{\bf R}_b \end{array} \right]$

To initialize such a velocity twist matrix where translation is not taken into account you can proceed like in the following code:

#include <visp3/core/vpVelocityTwistMatrix.h>
 
#ifdef ENABLE_VISP_NAMESPACE
using namespace VISP_NAMESPACE_NAME;
#endif
 
int main()
{
  vpRotationMatrix cRe( {0,  0, -1,
                        0, -1,  0,
                        -1,  0,  0} );
 
  vpVelocityTwistMatrix cVe(cRe);
  std::cout << "cVe:\n" << cVe << std::endl;
}

It produces the following printings:

cVe:
0  -1  0  0  0
-1  0  0  0  0
-1  0  0  0  0  0
0  0  0  0  -1
0  0  0  -1  0
0  0  -1  0  0

The code below shows how to convert a velocity skew expressed at the origin of the camera frame into the origin of the fix frame using the full velocity twist matrix.

#include <visp3/core/vpColVector.h>
#include <visp3/core/vpVelocityTwistMatrix.h>
 
#ifdef ENABLE_VISP_NAMESPACE
using namespace VISP_NAMESPACE_NAME;
#endif
 
int main()
{
  vpVelocityTwistMatrix fVc; // Twist transformation matrix from fix to camera frame
 
  vpHomogeneousMatrix fMc; // Fix to camera frame transformation
  // ... fMc need here to be initialized
 
  fVc.buildFrom(fMc);
 
  vpColVector c_v(6); // Velocity in the camera frame: vx,vy,vz,wx,wy,wz
  // ... c_v should here have an initial value
 
  vpColVector f_v(6); // Velocity in the fix frame: vx,vy,vz,wx,wy,wz
 
  // Compute the velocity in the fix frame
  f_v = fVc * c_v;
}

Examples: manServo4PointsDisplay.cpp, manSimu4Dots.cpp, manSimu4Points.cpp, mbot-apriltag-2D-half-vs.cpp, mbot-apriltag-ibvs.cpp, mbot-apriltag-pbvs.cpp, perfMatrixMultiplication.cpp, servoAfma4Point2DArtVelocity.cpp, servoAfma6FourPoints2DArtVelocity.cpp, servoAfma6Point2DArtVelocity.cpp, servoBebop2.cpp, servoBiclopsPoint2DArtVelocity.cpp, servoFlirPtuIBVS.cpp, servoPioneerPanSegment3D.cpp, servoPioneerPoint2DDepth.cpp, servoPioneerPoint2DDepthWithoutVpServo.cpp, servoPololuPtuPoint2DJointVelocity.cpp, servoPtu46Point2DArtVelocity.cpp, servoSimu4Points.cpp, servoSimuCylinder.cpp, servoSimuFourPoints2DCamVelocity.cpp, servoSimuFourPoints2DCamVelocityDisplay.cpp, servoSimuFourPoints2DPolarCamVelocityDisplay.cpp, servoSimuPoint2DCamVelocity2.cpp, servoSimuPoint2DCamVelocity3.cpp, servoSimuSphere.cpp, servoViper650FourPoints2DArtVelocityLs_cur.cpp, servoViper850FourPoints2DArtVelocityLs_cur.cpp, servoViper850FourPoints2DArtVelocityLs_des.cpp, servoViper850Point2DArtVelocity-jointAvoidance-basic.cpp, servoViper850Point2DArtVelocity-jointAvoidance-gpa.cpp, servoViper850Point2DArtVelocity-jointAvoidance-large.cpp, servoViper850Point2DArtVelocity.cpp, simulateFourPoints2DCartesianCamVelocity.cpp, simulateFourPoints2DPolarCamVelocity.cpp, testMatrix.cpp, testRobotViper650-frames.cpp, testRobotViper850-frames.cpp, testTwistMatrix.cpp, testVirtuoseAfma6.cpp, testVirtuoseHapticBox.cpp, tutorial-flir-ptu-ibvs.cpp, tutorial-simu-pioneer-continuous-gain-adaptive.cpp, tutorial-simu-pioneer-continuous-gain-constant.cpp, tutorial-simu-pioneer-pan.cpp, and tutorial-simu-pioneer.cpp.

Definition at line 174 of file vpVelocityTwistMatrix.h.

Constructor & Destructor Documentation

◆ vpVelocityTwistMatrix() [1/8]

vpVelocityTwistMatrix::vpVelocityTwistMatrix ( )

Initialize a velocity twist transformation matrix as identity.

Definition at line 87 of file vpVelocityTwistMatrix.cpp.

References eye().

◆ vpVelocityTwistMatrix() [2/8]

vpVelocityTwistMatrix::vpVelocityTwistMatrix ( const vpVelocityTwistMatrix & V )

Initialize a velocity twist transformation matrix from another velocity twist matrix.

Parameters

V	: Velocity twist matrix used as initializer.

Definition at line 95 of file vpVelocityTwistMatrix.cpp.

◆ vpVelocityTwistMatrix() [3/8]

vpVelocityTwistMatrix::vpVelocityTwistMatrix	(	const vpHomogeneousMatrix &	M,
		bool	full = `true`
	)

Initialize a velocity twist transformation matrix from an homogeneous matrix with

${\bf M} = \left[\begin{array}{cc} {\bf R} & {\bf t} \\ {\bf 0}_{1\times 3} & 1 \end{array} \right]$

Parameters

M : Homogeneous matrix $\bf M$ used to initialize the velocity twist transformation matrix.

full

: Boolean used to indicate which matrix should be filled.

When set to true, use the complete velocity skew transformation :
${\bf V} = \left[\begin{array}{cc} {\bf R} & [{\bf t}]_\times \; {\bf R} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$
When set to false, use the block diagonal velocity skew transformation:
${\bf V} = \left[\begin{array}{cc} {\bf R} & {\bf 0}_{3\times 3} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Definition at line 115 of file vpVelocityTwistMatrix.cpp.

References buildFrom(), and vpHomogeneousMatrix::getRotationMatrix().

◆ vpVelocityTwistMatrix() [4/8]

vpVelocityTwistMatrix::vpVelocityTwistMatrix	(	const vpTranslationVector &	t,
		const vpRotationMatrix &	R
	)

Initialize a velocity twist transformation matrix from a translation vector t and a rotation matrix R.

${\bf V} = \left[\begin{array}{cc} {\bf R} & [{\bf t}]_\times \; {\bf R} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Parameters

t	: Translation vector.
R	: Rotation matrix.

Definition at line 175 of file vpVelocityTwistMatrix.cpp.

References buildFrom(), and vpArray2D< double >::t().

◆ vpVelocityTwistMatrix() [5/8]

vpVelocityTwistMatrix::vpVelocityTwistMatrix	(	const vpTranslationVector &	t,
		const vpThetaUVector &	thetau
	)

Initialize a velocity twist transformation matrix from a translation vector t and a rotation vector with $\theta u$ parametrization.

${\bf V} = \left[\begin{array}{cc} {\bf R} & [{\bf t}]_\times \; {\bf R} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Parameters

t	: Translation vector.
thetau	: $\theta u$ rotation vector used to initialize rotation vector .

Definition at line 139 of file vpVelocityTwistMatrix.cpp.

References buildFrom(), and vpArray2D< double >::t().

◆ vpVelocityTwistMatrix() [6/8]

vpVelocityTwistMatrix::vpVelocityTwistMatrix	(	double	tx,
		double	ty,
		double	tz,
		double	tux,
		double	tuy,
		double	tuz
	)

Initialize a velocity twist transformation matrix from a translation vector ${\bf t}=(t_x, t_y, t_z)^T$ and a rotation vector with $\theta {\bf u}=(\theta u_x, \theta u_y, \theta u_z)^T$ parametrization.

${\bf V} = \left[\begin{array}{cc} {\bf R} & [{\bf t}]_\times \; {\bf R} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Parameters

tx,ty,tz	: Translation vector in meters.
tux,tuy,tuz	: $\theta {\bf u}$ rotation vector expressed in radians used to initialize .

Definition at line 209 of file vpVelocityTwistMatrix.cpp.

References buildFrom(), and vpArray2D< double >::t().

◆ vpVelocityTwistMatrix() [7/8]

vpVelocityTwistMatrix::vpVelocityTwistMatrix ( const vpRotationMatrix & R )

Initialize a velocity twist transformation matrix from a rotation matrix R.

${\bf V} = \left[\begin{array}{cc} {\bf R} & {\bf 0}_{3\times 3} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Parameters

R	: Rotation matrix.

Definition at line 192 of file vpVelocityTwistMatrix.cpp.

References buildFrom().

◆ vpVelocityTwistMatrix() [8/8]

vpVelocityTwistMatrix::vpVelocityTwistMatrix ( const vpThetaUVector & thetau )

Initialize a velocity twist transformation matrix from a rotation vector with $\theta u$ parametrization.

${\bf V} = \left[\begin{array}{cc} {\bf R} & {\bf 0}_{3\times 3}\\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Parameters

thetau : $\theta u$ rotation vector used to initialize rotation vector .

Definition at line 157 of file vpVelocityTwistMatrix.cpp.

References buildFrom().

Member Function Documentation

◆ buildFrom() [1/5]

vpVelocityTwistMatrix & vpVelocityTwistMatrix::buildFrom	(	const vpHomogeneousMatrix &	M,
		bool	full = `true`
	)

Initialize a velocity twist transformation matrix from an homogeneous matrix with

${\bf M} = \left[\begin{array}{cc} {\bf R} & {\bf t} \\ {\bf 0}_{1\times 3} & 1 \end{array} \right]$

Parameters

M : Homogeneous matrix used to initialize the velocity twist transformation matrix.

full

: Boolean used to indicate which matrix should be filled.

When set to true, use the complete velocity skew transformation :
${\bf V} = \left[\begin{array}{cc} {\bf R} & [{\bf t}]_\times \; {\bf R} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$
When set to false, use the block diagonal velocity skew transformation:
${\bf V} = \left[\begin{array}{cc} {\bf R} & {\bf 0}_{3\times 3} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Definition at line 449 of file vpVelocityTwistMatrix.cpp.

References buildFrom(), vpHomogeneousMatrix::getRotationMatrix(), and vpHomogeneousMatrix::getTranslationVector().

◆ buildFrom() [2/5]

vpVelocityTwistMatrix & vpVelocityTwistMatrix::buildFrom ( const vpRotationMatrix & R )

Build a velocity twist transformation block diagonal matrix from a rotation matrix R.

${\bf V} = \left[\begin{array}{cc} {\bf R} & {\bf 0}_{3\times 3} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Parameters

R	: Rotation matrix.

Definition at line 349 of file vpVelocityTwistMatrix.cpp.

◆ buildFrom() [3/5]

vpVelocityTwistMatrix & vpVelocityTwistMatrix::buildFrom ( const vpThetaUVector & thetau )

Initialize a velocity twist transformation matrix from a rotation vector with $\theta u$ parametrization.

${\bf V} = \left[\begin{array}{cc} {\bf R} & {\bf 0}_{3\times 3} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Parameters

thetau : $\theta {\bf u}$ rotation vector used to create rotation matrix ${\bf R}$ .

Definition at line 425 of file vpVelocityTwistMatrix.cpp.

References buildFrom().

◆ buildFrom() [4/5]

vpVelocityTwistMatrix & vpVelocityTwistMatrix::buildFrom	(	const vpTranslationVector &	t,
		const vpRotationMatrix &	R
	)

Build a velocity twist transformation matrix from a translation vector t and a rotation matrix R.

${\bf V} = \left[\begin{array}{cc} {\bf R} & [{\bf t}]_\times \; {\bf R} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Parameters

t	: Translation vector.
R	: Rotation matrix.

Definition at line 376 of file vpVelocityTwistMatrix.cpp.

References vpArray2D< double >::t().

Referenced by buildFrom(), vpMbDepthDenseTracker::computeVVS(), vpMbDepthNormalTracker::computeVVS(), vpMbEdgeTracker::computeVVS(), vpMbGenericTracker::computeVVS(), vpMbEdgeTracker::computeVVSFirstPhasePoseEstimation(), vpMbTracker::computeVVSPoseEstimation(), vpRobotFlirPtu::get_cVe(), vpUnicycle::get_cVe(), vpPtu46::get_cVe(), vpRobotAfma6::get_cVe(), vpRobotPtu46::get_cVe(), vpAfma4::get_cVe(), vpAfma6::get_cVe(), vpBiclops::get_cVe(), vpRobotAfma4::get_cVe(), vpRobotBiclops::get_cVe(), vpRobotViper650::get_cVe(), vpRobotViper850::get_cVe(), vpViper::get_cVe(), vpAfma4::get_cVf(), inverse(), vpRobotAfma4::setVelocity(), and vpVelocityTwistMatrix().

◆ buildFrom() [5/5]

vpVelocityTwistMatrix & vpVelocityTwistMatrix::buildFrom	(	const vpTranslationVector &	t,
		const vpThetaUVector &	thetau
	)

Initialize a velocity twist transformation matrix from a translation vector t and a rotation vector with $\theta u$ parametrization.

${\bf V} = \left[\begin{array}{cc} {\bf R} & [{\bf t}]_\times \; {\bf R} \\ {\bf 0}_{3\times 3} & {\bf R} \end{array} \right]$

Parameters

t	: Translation vector.
thetau	: $\theta {\bf u}$ rotation vector used to create rotation matrix ${\bf R}$ .

Definition at line 407 of file vpVelocityTwistMatrix.cpp.

References buildFrom(), and vpArray2D< double >::t().

◆ conv2() [1/2]

vpArray2D< double > vpArray2D< double >::conv2	(	const vpArray2D< Type > &	M,
		const vpArray2D< Type > &	kernel,
		const std::string &	mode
	)

staticinherited

Perform a 2D convolution similar to Matlab conv2 function: $M \star kernel$ .

Parameters

M	: First matrix.
kernel	: Second matrix.
mode	: Convolution mode: "full" (default), "same", "valid".

Convolution mode: full, same, valid (image credit: Theano doc).

Note: This is a very basic implementation that does not use FFT.

Definition at line 1053 of file vpArray2D.h.

◆ conv2() [2/2]

void vpArray2D< double >::conv2	(	const vpArray2D< Type > &	M,
		const vpArray2D< Type > &	kernel,
		vpArray2D< Type > &	res,
		const std::string &	mode
	)

staticinherited

Perform a 2D convolution similar to Matlab conv2 function: $M \star kernel$ .

Parameters

M	: First array.
kernel	: Second array.
res	: Result.
mode	: Convolution mode: "full" (default), "same", "valid".

Convolution mode: full, same, valid (image credit: Theano doc).

Note: This is a very basic implementation that does not use FFT.

Definition at line 1067 of file vpArray2D.h.

◆ extract() [1/2]

void vpVelocityTwistMatrix::extract ( vpRotationMatrix & R ) const

Extract the rotation matrix from the velocity twist matrix.

Definition at line 481 of file vpVelocityTwistMatrix.cpp.

Referenced by extract(), and inverse().

◆ extract() [2/2]

void vpVelocityTwistMatrix::extract ( vpTranslationVector & t ) const

Extract the translation vector from the velocity twist matrix.

Definition at line 492 of file vpVelocityTwistMatrix.cpp.

References extract(), and vpRotationMatrix::t().

◆ eye()

void vpVelocityTwistMatrix::eye ( )

Initialize a 6x6 velocity twist matrix as identity.

Definition at line 69 of file vpVelocityTwistMatrix.cpp.

Referenced by vpVelocityTwistMatrix().

◆ getCols()

unsigned int vpArray2D< double >::getCols ( ) const

inlineinherited

Return the number of columns of the 2D array.

See also: getRows(), size()

Definition at line 337 of file vpArray2D.h.

◆ getMaxValue()

double vpArray2D< double >::getMaxValue

inherited

Return the array max value.

Examples: servoMomentImage.cpp.

Definition at line 339 of file vpArray2D.h.

◆ getMinValue()

double vpArray2D< double >::getMinValue

inherited

Return the array min value.

Examples: servoMomentImage.cpp.

Definition at line 341 of file vpArray2D.h.

◆ getRows()

unsigned int vpArray2D< double >::getRows ( ) const

inlineinherited

◆ hadamard()

vpArray2D< double > vpArray2D< double >::hadamard ( const vpArray2D< Type > & m ) const

inherited

Compute the Hadamard product (element wise matrix multiplication).

Parameters

m	: Second matrix;

Returns: m1.hadamard(m2) The Hadamard product : $m1 \circ m2 = (m1 \circ m2)_{i,j} = (m1)_{i,j} (m2)_{i,j}$

Definition at line 641 of file vpArray2D.h.

◆ insert() [1/2]

vpArray2D< double > vpArray2D< double >::insert	(	const vpArray2D< Type > &	A,
		const vpArray2D< Type > &	B,
		unsigned int	r,
		unsigned int	c
	)

inherited

Insert array B in array A at the given position.

Parameters

A	: Main array.
B	: Array to insert.
r	: Index of the row where to add the array.
c	: Index of the column where to add the array.

Returns: Array with B insert in A.

Warning: Throw exception if the sizes of the arrays do not allow the insertion.

Definition at line 1081 of file vpArray2D.h.

◆ insert() [2/2]

void vpArray2D< double >::insert	(	const vpArray2D< Type > &	A,
		unsigned int	r,
		unsigned int	c
	)

inlineinherited

Insert array A at the given position in the current array.

Warning: Throw vpException::dimensionError if the dimensions of the matrices do not allow the operation.

Parameters

A	: The array to insert.
r	: The index of the row to begin to insert data.
c	: The index of the column to begin to insert data.

Definition at line 497 of file vpArray2D.h.

◆ inverse() [1/2]

vpVelocityTwistMatrix vpVelocityTwistMatrix::inverse ( ) const

Invert the velocity twist matrix.

Definition at line 462 of file vpVelocityTwistMatrix.cpp.

References buildFrom(), extract(), and vpRotationMatrix::t().

Referenced by inverse().

◆ inverse() [2/2]

void vpVelocityTwistMatrix::inverse ( vpVelocityTwistMatrix & V ) const

Invert the velocity twist matrix.

Definition at line 478 of file vpVelocityTwistMatrix.cpp.

References inverse().

◆ load()

static bool vpArray2D< double >::load	(	const std::string &	filename,
		vpArray2D< Type > &	A,
		bool	binary = `false`,
		char *	header = `nullptr`
	)

inlinestaticinherited

Load a matrix from a file.

Parameters

filename	: Absolute file name.
A	: Array to be loaded
binary	: If true the matrix is loaded from a binary file, else from a text file.
header	: Header of the file is loaded in this parameter.

Returns: Returns true if success.

See also: save()

Definition at line 669 of file vpArray2D.h.

◆ loadYAML()

static bool vpArray2D< double >::loadYAML	(	const std::string &	filename,
		vpArray2D< Type > &	A,
		char *	header = `nullptr`
	)

inlinestaticinherited

Load an array from a YAML-formatted file.

Parameters

filename	: absolute file name.
A	: array to be loaded from the file.
header	: header of the file is loaded in this parameter.

Returns: Returns true on success.

See also: saveYAML()

Examples: servoFlirPtuIBVS.cpp, servoFrankaIBVS.cpp, servoFrankaPBVS.cpp, servoUniversalRobotsIBVS.cpp, servoUniversalRobotsPBVS.cpp, tutorial-flir-ptu-ibvs.cpp, tutorial-hsv-segmentation-pcl-viewer.cpp, tutorial-hsv-segmentation-pcl.cpp, and tutorial-hsv-segmentation.cpp.

Definition at line 783 of file vpArray2D.h.

◆ operator!=()

bool operator!= ( const vpArray2D< Type > & A ) const

inherited

Not equal to comparison operator of a 2D array.

Definition at line 523 of file vpArray2D.h.

◆ operator*() [1/3]

vpColVector vpVelocityTwistMatrix::operator* ( const vpColVector & v ) const

Operator that allows to multiply a twist transformation matrix by a 6-dimension column vector.

Parameters

v	: Velocity skew vector.

Exceptions

vpException::dimensionError If v is not a 6 dimension column vector.

Definition at line 315 of file vpVelocityTwistMatrix.cpp.

References vpException::dimensionError, vpArray2D< Type >::getRows(), and vpArray2D< double >::rowPtrs.

◆ operator*() [2/3]

vpMatrix vpVelocityTwistMatrix::operator* ( const vpMatrix & M ) const

Operator that allows to multiply a velocity twist transformation matrix by a matrix.

As shown in the example below, this operator can be used to compute the corresponding camera velocity skew from the joint velocities knowing the robot jacobian.

#include <visp3/core/vpColVector.h>
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpVelocityTwistMatrix.h>
#include <visp3/robot/vpSimulatorCamera.h>
 
#ifdef ENABLE_VISP_NAMESPACE
using namespace VISP_NAMESPACE_NAME;
#endif
 
int main()
{
  vpSimulatorCamera robot;
 
  vpColVector q_vel(6); // Joint velocity on the 6 joints
  // ... q_vel need here to be initialized
 
  vpColVector c_v(6); // Velocity in the camera frame: vx,vy,vz,wx,wy,wz
 
  vpVelocityTwistMatrix cVe;  // Velocity skew transformation from camera frame to end-effector
  robot.get_cVe(cVe);
 
  vpMatrix eJe;       // Robot jacobian
  robot.get_eJe(eJe);
 
  // Compute the velocity in the camera frame
  c_v = cVe * eJe * q_vel;
 
  return 0;
}

Exceptions

vpException::dimensionError If M is not a 6 rows dimension matrix.

Definition at line 282 of file vpVelocityTwistMatrix.cpp.

References vpException::dimensionError, vpArray2D< Type >::getCols(), vpArray2D< Type >::getRows(), and vpArray2D< double >::rowPtrs.

◆ operator*() [3/3]

vpVelocityTwistMatrix vpVelocityTwistMatrix::operator* ( const vpVelocityTwistMatrix & V ) const

Operator that allows to multiply a velocity twist transformation matrix by an other velocity twist transformation matrix.

Definition at line 223 of file vpVelocityTwistMatrix.cpp.

References vpArray2D< Type >::rowPtrs, and vpArray2D< double >::rowPtrs.

◆ operator=()

BEGIN_VISP_NAMESPACE vpVelocityTwistMatrix & vpVelocityTwistMatrix::operator= ( const vpVelocityTwistMatrix & V )

Copy operator that allow to set a velocity twist matrix from an other one.

Parameters

V	: Velocity twist matrix to copy.

Definition at line 55 of file vpVelocityTwistMatrix.cpp.

References vpArray2D< Type >::rowPtrs, and vpArray2D< double >::rowPtrs.

◆ operator==()

bool vpArray2D< double >::operator== ( const vpArray2D< Type > & A ) const

inherited

Equal to comparison operator of a 2D array.

Definition at line 519 of file vpArray2D.h.

◆ operator[]() [1/2]

double * vpArray2D< double >::operator[] ( unsigned int i )

inlineinherited

Set element $A_{ij} = x$ using A[i][j] = x.

Definition at line 605 of file vpArray2D.h.

◆ operator[]() [2/2]

double * vpArray2D< double >::operator[] ( unsigned int i ) const

inlineinherited

Get element $x = A_{ij}$ using x = A[i][j].

Definition at line 607 of file vpArray2D.h.

◆ print()

int vpVelocityTwistMatrix::print	(	std::ostream &	s,
		unsigned int	length,
		char const *	intro = `0`
	)		const

Pretty print a velocity twist matrix. The data are tabulated. The common widths before and after the decimal point are set with respect to the parameter maxlen.

Parameters

s	Stream used for the printing.
length	The suggested width of each matrix element. The actual width grows in order to accommodate the whole integral part, and shrinks if the whole extent is not needed for all the numbers.
intro	The introduction which is printed before the matrix. Can be set to zero (or omitted), in which case the introduction is not printed.

Returns: Returns the common total width for all matrix elements

See also: std::ostream &operator<<(std::ostream &s, const vpArray2D<Type> &A)

Examples: testTwistMatrix.cpp.

Definition at line 532 of file vpVelocityTwistMatrix.cpp.

References vpArray2D< double >::getCols(), vpArray2D< double >::getRows(), vpMath::maximum(), and vpArray2D< double >::size().

◆ reshape()

void vpArray2D< double >::reshape	(	unsigned int	nrows,
		unsigned int	ncols
	)

inlineinherited

Examples: testMatrixInitialization.cpp.

Definition at line 456 of file vpArray2D.h.

◆ resize() [1/2]

void vpVelocityTwistMatrix::resize	(	unsigned int	nrows,
		unsigned int	ncols,
		bool	flagNullify = `true`
	)

inline

This function is not applicable to a velocity twist matrix that is always a 6-by-6 matrix.

Exceptions

vpException::fatalError When this function is called.

Definition at line 223 of file vpVelocityTwistMatrix.h.

References vpException::fatalError.

◆ resize() [2/2]

void vpArray2D< double >::resize	(	unsigned int	nrows,
		unsigned int	ncols,
		bool	flagNullify = `true`,
		bool	recopy_ = `true`
	)

inlineinherited

Set the size of the array and initialize all the values to zero.

Parameters

nrows	: number of rows.
ncols	: number of column.
flagNullify	: if true, then the array is re-initialized to 0 after resize. If false, the initial values from the common part of the array (common part between old and new version of the array) are kept. Default value is true.
recopy_	: if true, will perform an explicit recopy of the old data.

Examples: catchArray2D.cpp, catchJsonArrayConversion.cpp, catchParticleFilter.cpp, perfMatrixMultiplication.cpp, perfMatrixTranspose.cpp, testMatrix.cpp, testMatrixDeterminant.cpp, testMatrixInverse.cpp, testMatrixPseudoInverse.cpp, and testSvd.cpp.

Definition at line 362 of file vpArray2D.h.

◆ save()

static bool vpArray2D< double >::save	(	const std::string &	filename,
		const vpArray2D< Type > &	A,
		bool	binary = `false`,
		const char *	header = `""`
	)

inlinestaticinherited

Save a matrix to a file.

Parameters

filename	: Absolute file name.
A	: Array to be saved.
binary	: If true the matrix is saved in a binary file, else a text file.
header	: Optional line that will be saved at the beginning of the file.

Returns: Returns true if success.

Warning : If you save the matrix as in a text file the precision is less than if you save it in a binary file.

See also: load()

Definition at line 874 of file vpArray2D.h.

◆ saveYAML()

static bool vpArray2D< double >::saveYAML	(	const std::string &	filename,
		const vpArray2D< Type > &	A,
		const char *	header = `""`
	)

inlinestaticinherited

Save an array in a YAML-formatted file.

Parameters

filename	: absolute file name.
A	: array to be saved in the file.
header	: optional lines that will be saved at the beginning of the file. Should be YAML-formatted and will adapt to the indentation if any.

Returns: Returns true if success.

Here is an example of outputs.

vpArray2D<double> M(3,4);
vpArray2D::saveYAML("matrix.yml", M, "example: a YAML-formatted header");
vpArray2D::saveYAML("matrixIndent.yml", M, "example:\n    - a YAML-formatted \
header\n    - with inner indentation");

Content of matrix.yml:

example: a YAML-formatted header
rows: 3
cols: 4
data:
  - [0, 0, 0, 0]
  - [0, 0, 0, 0]
  - [0, 0, 0, 0]

Content of matrixIndent.yml:

example:
    - a YAML-formatted header
    - with inner indentation
rows: 3
cols: 4
data:
    - [0, 0, 0, 0]
    - [0, 0, 0, 0]
    - [0, 0, 0, 0]

See also: loadYAML()

Definition at line 972 of file vpArray2D.h.

◆ size()

unsigned int vpArray2D< double >::size ( ) const

inlineinherited

Return the number of elements of the 2D array.

Definition at line 349 of file vpArray2D.h.

◆ t()

vpArray2D< double > vpArray2D< double >::t

inherited

Compute the transpose of the array.

Returns: vpArray2D<Type> C = A^T

Definition at line 648 of file vpArray2D.h.

Friends And Related Function Documentation

◆ insert()

void vpArray2D< double >::insert	(	const vpArray2D< Type > &	A,
		const vpArray2D< Type > &	B,
		vpArray2D< Type > &	C,
		unsigned int	r,
		unsigned int	c
	)

Parameters

A	: Main array.
B	: Array to insert.
C	: Result array.
r	: Index of the row where to insert array B.
c	: Index of the column where to insert array B.

Warning: Throw exception if the sizes of the arrays do not allow the insertion.

Definition at line 1096 of file vpArray2D.h.

◆ operator!=()

bool operator!= ( const vpArray2D< Type > & A ) const

◆ operator==() [1/2]

bool operator== ( const vpArray2D< double > & A ) const

◆ operator==() [2/2]

bool operator== ( const vpArray2D< float > & A ) const

◆ vpGEMM()

void vpGEMM	(	const vpArray2D< double > &	A,
		const vpArray2D< double > &	B,
		const double &	alpha,
		const vpArray2D< double > &	C,
		const double &	beta,
		vpArray2D< double > &	D,
		const unsigned int &	ops = `0`
	)

For example, to compute D = alpha*A^T*B^T+beta*C we need to call :

vpGEMM(A, B, alpha, C, beta, D, VP_GEMM_A_T + VP_GEMM_B_T);

vpArray2D< double >::vpGEMM

void vpGEMM(const vpArray2D< double > &A, const vpArray2D< double > &B, const double &alpha, const vpArray2D< double > &C, const double &beta, vpArray2D< double > &D, const unsigned int &ops=0)

Definition: vpGEMM.h:414

If C is not used, vpGEMM must be called using an empty array null. Thus to compute D = alpha*A^T*B, we have to call:

vpGEMM(A, B, alpha, null, 0, D, VP_GEMM_B_T);

Exceptions

vpException::incorrectMatrixSizeError if the sizes of the matrices do not allow the operations.

Parameters

A	: An array that could be a vpMatrix.
B	: An array that could be a vpMatrix.
alpha	: A scalar.
C	: An array that could be a vpMatrix.
beta	: A scalar.
D	: The resulting array that could be a vpMatrix.
ops	: A scalar describing operation applied on the matrices. Possible values are the one defined in vpGEMMmethod(): VP_GEMM_A_T, VP_GEMM_B_T, VP_GEMM_C_T.

Definition at line 414 of file vpGEMM.h.

◆ vpGEMMmethod

enum vpGEMMmethod

Operations are :

VP_GEMM_A_T to use the transpose matrix of A instead of the matrix A
VP_GEMM_B_T to use the transpose matrix of B instead of the matrix B
VP_GEMM_C_T to use the transpose matrix of C instead of the matrix C

Definition at line 53 of file vpGEMM.h.

◆ vpMatrix

friend class vpMatrix

friend

Definition at line 176 of file vpVelocityTwistMatrix.h.

Member Data Documentation

◆ colNum

unsigned int vpArray2D< double >::colNum

protectedinherited

Number of columns in the array.

Definition at line 1103 of file vpArray2D.h.

◆ data

double * vpArray2D< double >::data

inherited

Address of the first element of the data array.

Examples: catchArray2D.cpp, catchQuaternion.cpp, catchRotation.cpp, perfMatrixMultiplication.cpp, testDisplacement.cpp, testMatrix.cpp, testTranslationVector.cpp, testUniversalRobotsGetData.cpp, tutorial-bridge-opencv-matrix.cpp, and tutorial-matlab.cpp.

Definition at line 148 of file vpArray2D.h.

◆ dsize

unsigned int vpArray2D< double >::dsize

protectedinherited

Current array size (rowNum * colNum)

Definition at line 1107 of file vpArray2D.h.

◆ rowNum

unsigned int vpArray2D< double >::rowNum

protectedinherited

Number of rows in the array.

Definition at line 1101 of file vpArray2D.h.

◆ rowPtrs

double ** vpArray2D< double >::rowPtrs

protectedinherited

Address of the first element of each rows.

Definition at line 1105 of file vpArray2D.h.

Public Member Functions

Public Attributes

Friends

Related Functions

Inherited I/O from vpArray2D with Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ vpVelocityTwistMatrix() [1/8]

◆ vpVelocityTwistMatrix() [2/8]

◆ vpVelocityTwistMatrix() [3/8]

◆ vpVelocityTwistMatrix() [4/8]

◆ vpVelocityTwistMatrix() [5/8]

◆ vpVelocityTwistMatrix() [6/8]

◆ vpVelocityTwistMatrix() [7/8]

◆ vpVelocityTwistMatrix() [8/8]

Member Function Documentation

◆ buildFrom() [1/5]

◆ buildFrom() [2/5]

◆ buildFrom() [3/5]

◆ buildFrom() [4/5]

◆ buildFrom() [5/5]

◆ conv2() [1/2]

◆ conv2() [2/2]

◆ extract() [1/2]

◆ extract() [2/2]

◆ eye()

◆ getCols()

◆ getMaxValue()

◆ getMinValue()

◆ getRows()

◆ hadamard()

◆ insert() [1/2]

◆ insert() [2/2]

◆ inverse() [1/2]

◆ inverse() [2/2]

◆ load()

◆ loadYAML()

◆ operator!=()

◆ operator*() [1/3]

◆ operator*() [2/3]

◆ operator*() [3/3]

◆ operator=()

◆ operator==()

◆ operator[]() [1/2]

◆ operator[]() [2/2]

◆ print()

◆ reshape()

◆ resize() [1/2]

◆ resize() [2/2]

◆ save()

◆ saveYAML()

◆ size()

◆ t()

Friends And Related Function Documentation

◆ insert()

◆ operator!=()

◆ operator==() [1/2]

◆ operator==() [2/2]

◆ vpGEMM()

◆ vpGEMMmethod

◆ vpMatrix

Member Data Documentation

◆ colNum

◆ data

◆ dsize

◆ rowNum

◆ rowPtrs