bearing_constraint Class Reference

List of all members.

Public Members
		bearing_constraint ( const double u, const double b )
		The only constructur for a `bearing_constraint.` More...
	virtual	~bearing_constraint (void)
	virtual void	energy ( const double tol, const vector< vector2 > &p, double &e, vector< vector2 > &dedp ) const
		Calculate a dimensionless measure of the potential energy (e) of the `constraint.` More...
	double	wanted_bearing (void) const
		Get the wanted bearing. More...
	void	wanted_bearing ( const double b )
		Change the wanted bearing. More...
Friends
	void	assoc ( bearing_constraint &c, vector2 &p0, vector2 &p1 )
		Associates a `bearing_constraint` with the 2 points it constrains. More...
	void	unassoc ( bearing_constraint &c )
		Disassociates a `bearing_constraint` from the points it constrains. More...

Detailed Description

Constrain the bearing of a point, as measured from a second point.

Definition at line 40 of file bearing_constraint.h.

Member Function Documentation

bearing_constraint::bearing_constraint (const double u, const double b)

The only constructur for a bearing_constraint.

Parameters:

u	the degree of uncertainty in the constriant.
a	the bearing to which the points should be constrained.

Postconditions:

 assert( this->uncertainty() == u );
 assert( this->wanted_bearing() == b );
 assert( this->points().size() == 2 );

Definition at line 40 of file bearing_constraint.cpp.

bearing_constraint::~bearing_constraint (void) [virtual]

Definition at line 60 of file bearing_constraint.cpp.

void bearing_constraint::energy (const double tol, const vector<vector2>& p, double & e, vector<vector2>& dedp) const [virtual]

Calculate a dimensionless measure of the potential energy (e) of the constraint.

This is equivalent to a measure of how poorly the constraint is satisfied. If *(this->points()[i]) had position p[i], it calculates the energy (e) and the rates of change of that energy (dedp) with respect to the point positions. Larger values indicate the constraint is less well satisfied. 0 is the minimum possible energy, and energy <= 1 indicates that the constraint is satisifed to within the uncertainty of the constraint.

Parameters:

tol	is a dimensionless calculation tolerance.
p	are the point positions.

Return values:

e	the energy.
dedp	is the rate of change of energy with position.

Preconditions:

 assert( p.size() == 2 );
 assert( 0 < tol && tol < 1 );

Postconditions:

 assert( dedp.size() == 2 );

Reimplemented from constraint.

Definition at line 67 of file bearing_constraint.cpp.

double bearing_constraint::wanted_bearing (void) const [inline]

Get the wanted bearing.

The expected bearing of points()[1] from points()[0], in radians clockwise from north. Beware of confusion with the angle used for angle_constraint objects, which is positive anticlockwise. North is the direction (0,1), that is, the y-axis of the coordinate system.

Returns:: The wanted bearing.

Definition at line 155 of file bearing_constraint.h.

void bearing_constraint::wanted_bearing (const double d)

Change the wanted bearing.

Parameters:

b	the new wanted angle.

Preconditions:

 assert( 0.0 <= b && b < 2*pi);

Postconditions:

 assert( this->wanted_bearing() == b );

Definition at line 124 of file bearing_constraint.cpp.

Friends And Related Function Documentation

void assoc (bearing_constraint & c, vector2 & p0, vector2 & p1) [friend]

Associates a bearing_constraint with the 2 points it constrains.

Preconditions:

 assert( !c.points()[0] );
 assert( !c.points()[1] );

Postconditions:

 assert( c.points()[0] == &p0 );
 assert( c.points()[1] == &p1 );

Definition at line 83 of file bearing_constraint.h.

void unassoc (bearing_constraint & c) [friend]

Disassociates a bearing_constraint from the points it constrains.

Postconditions:

 assert( !c.points()[0] );
 assert( !c.points()[1] );

Definition at line 103 of file bearing_constraint.h.

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

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bearing_constraint Class Reference

Public Members

Friends

Detailed Description

Member Function Documentation

Friends And Related Function Documentation