gtsam::Line3 Class Reference

Public Member Functions
	Line3 ()
	Default constructor is the Z axis.
	Line3 (const Rot3 &R, const double a, const double b)
	Constructor for general line from (R, a, b)
Line3	retract (const Vector4 &v, OptionalJacobian< 4, 4 > Dp=boost::none, OptionalJacobian< 4, 4 > Dv=boost::none) const
	The retract method maps from the tangent space back to the manifold. More...
Vector4	localCoordinates (const Line3 &q, OptionalJacobian< 4, 4 > Dp=boost::none, OptionalJacobian< 4, 4 > Dq=boost::none) const
	The localCoordinates method is the inverse of retract and finds the difference between two lines in the tangent space. More...
void	print (const std::string &s="") const
	Print R, a, b. More...
bool	equals (const Line3 &l2, double tol=10e-9) const
	Check if two lines are equal. More...
Unit3	project (OptionalJacobian< 2, 4 > Dline=boost::none) const
	Projecting a line to the image plane. More...
Point3	point (double distance=0) const
	Returns point on the line that is at a certain distance starting from the point where the rotated XY axis intersects the line. More...
Rot3	R () const
	Return the rotation of the line.
double	a () const
	Return the x-coordinate of the intersection of the line with the xy plane.
double	b () const
	Return the y-coordinate of the intersection of the line with the xy plane.

Public Types
enum	{ dimension = 4 }

Friends
Line3	transformTo (const Pose3 &wTc, const Line3 &wL, OptionalJacobian< 4, 6 > Dpose, OptionalJacobian< 4, 4 > Dline)
	Transform a line from world to camera frame. More...

Member Function Documentation

equals()

bool gtsam::Line3::equals	(	const Line3 &	l2,
		double	tol = 10e-9
	)		const

Check if two lines are equal.

Parameters

l2	- line to be compared
tol	: optional tolerance

Returns

boolean - true if lines are equal

localCoordinates()

Vector4 gtsam::Line3::localCoordinates	(	const Line3 &	q,
		OptionalJacobian< 4, 4 >	Dp = boost::none,
		OptionalJacobian< 4, 4 >	Dq = boost::none
	)		const

The localCoordinates method is the inverse of retract and finds the difference between two lines in the tangent space.

It computes v = q - p where q is an input line, p is this line and v is their difference in the tangent space.

Parameters

q	Line3 on manifold
Dp	OptionalJacobian of localCoordinates with respect to this line
Dq	OptionalJacobian of localCoordinates with respect to this line

Returns

v: difference in the tangent space

point()

Point3 gtsam::Line3::point

(

double

distance = 0

)

const

Returns point on the line that is at a certain distance starting from the point where the rotated XY axis intersects the line.

Parameters

distance

(can be positive or negative) - positive is the positive direction of the rotated z axis that forms the line. The default value of zero returns the point where the rotated XY axis intersects the line.

Returns

Point on the line

print()

void gtsam::Line3::print

(

const std::string &

s = ""

)

const

Print R, a, b.

Parameters

s	optional starting string

project()

Unit3 gtsam::Line3::project

(

OptionalJacobian< 2, 4 >

Dline = boost::none

)

const

Projecting a line to the image plane.

Assumes this line is in camera frame.

Parameters

Dline

OptionalJacobian of projected line with respect to this line

Returns

Unit3 - projected line in image plane, in homogenous coordinates. We use Unit3 since it is a manifold with the right dimension.

retract()

Line3 gtsam::Line3::retract	(	const Vector4 &	v,
		OptionalJacobian< 4, 4 >	Dp = boost::none,
		OptionalJacobian< 4, 4 >	Dv = boost::none
	)		const

The retract method maps from the tangent space back to the manifold.

The method q = p + v, where p is this line, v is an increment along the tangent space and q is the resulting line. The tangent space for the rotation of a line is only two dimensional - rotation about x and y

Parameters

v	increment in tangent space
Dp	increment of retraction with respect to this line
Dv	Jacobian of retraction with respect to the increment

Returns

q: resulting line after adding the increment and mapping to the manifold

Friends And Related Function Documentation

transformTo

Line3 transformTo ( const Pose3 &  wTc, const Line3 &  wL, OptionalJacobian< 4, 6 >  Dpose, OptionalJacobian< 4, 4 >  Dline  )

friend

Transform a line from world to camera frame.

Parameters

wTc	- Pose3 of camera in world frame
wL	- Line3 in world frame
Dpose	- OptionalJacobian of transformed line with respect to p
Dline	- OptionalJacobian of transformed line with respect to l

Returns

Transformed line in camera frame

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

• /Users/dellaert/git/github/gtsam/geometry/Line3.h
• /Users/dellaert/git/github/gtsam/geometry/Line3.cpp