TLine2D Class Reference

A class to represent a line in 2D. More...

#include <TLine2D.h>

Public Member Functions
	TLine2D ()
	Constructors.
	TLine2D (double slope, double yOffset)
	TLine2D (const AList< TPoint2D > &)
virtual	~TLine2D ()
	Destructor.
double	slope (void) const
double	yOffset (void) const
double	xOffset (void) const
double	slope (double)
double	yOffset (double)
int	fit (void)
double	det (void) const
double	distance (const TPoint2D &) const
void	append (const TPoint2D &)
void	remove (const TPoint2D &)
const CAList< TPoint2D > &	list (void) const

Detailed Description

A class to represent a line in 2D.

Definition at line 25 of file TLine2D.h.

Constructor & Destructor Documentation

TLine2D() [1/3]

TLine2D::TLine2D

(

)

Constructors.

Definition at line 31 of file TLine2D.cxx.

                 : _slope(1), _yOffset(0), _det(0), _list(0) {
}

TLine2D() [2/3]

TLine2D::TLine2D	(	double	slope,
		double	yOffset
	)

Definition at line 34 of file TLine2D.cxx.

: _slope(a),
  _yOffset(b),
  _det(0),
  _list(0) {
}

TLine2D() [3/3]

TLine2D::TLine2D

(

const AList< TPoint2D > &

a

)

Definition at line 41 of file TLine2D.cxx.

                                          : _slope(1), _yOffset(0), _det(0) {
    _list = new CAList<TPoint2D>();
    _list->append(a);
}

~TLine2D()

TLine2D::~TLine2D ( )

virtual

Destructor.

Definition at line 46 of file TLine2D.cxx.

                  {
    if (_list) delete _list;
}

Member Function Documentation

append()

void TLine2D::append

(

const TPoint2D &

a

)

Definition at line 51 of file TLine2D.cxx.

                                  {
    if (! _list)
    _list = new CAList<TPoint2D>();
    _list->append(a);
}

det()

double TLine2D::det

(

void

)

const

distance()

double TLine2D::distance

(

const TPoint2D &

p

)

const

Definition at line 112 of file TLine2D.cxx.

                                          {
    double ydif = p.y() - _yOffset;
    double vmag = sqrt(1. + _slope * _slope);
    double dot = (p.x() + ydif * _slope) / vmag;
    double xmag2 = p.x() * p.x() + ydif * ydif;
    return sqrt(xmag2 - dot * dot);
}

fit()

int TLine2D::fit

(

void

)

Definition at line 71 of file TLine2D.cxx.

                 {
    if (! _list) return -1;
 
    unsigned n = _list->length();
    if (! n) return -1;
 
    if (n == 2) {
    double x0 = (* _list)[0]->x();
    double y0 = (* _list)[0]->y();
    double x1 = (* _list)[1]->x();
    double y1 = (* _list)[1]->y();
    if (x0 == x1) return -2;
    _slope = (y0 - y1) / (x0 - x1);
    _yOffset = - _slope * x1 + y1;
    
    return 0;
    }
 
    double sum = double(n);
    double sumX = 0., sumY = 0., sumX2 = 0., sumXY = 0., sumY2 = 0.;
    for (unsigned i = 0; i < n; i++) {
    const TPoint2D & p = * (* _list)[i];
    double x = p.x();
    double y = p.y();
    sumX  += x;
    sumY  += y;
    sumX2 += x * x;
    sumXY += x * y;
    sumY2 += y * y;
    }
 
    _det = sum * sumX2 - sumX * sumX;
    if (_det == 0.) return -3;
 
    _slope = (sumXY * sum - sumX * sumY) / _det;
    _yOffset = (sumX2 * sumY - sumX * sumXY) / _det;    
 
    return 0;
}

list()

const CAList< TPoint2D > & TLine2D::list

(

void

)

const

Definition at line 64 of file TLine2D.cxx.

                        {
    if (! _list)
    _list = new CAList<TPoint2D>();
    return * _list;
}

remove()

void TLine2D::remove

(

const TPoint2D &

a

)

Definition at line 58 of file TLine2D.cxx.

                                  {
    if (! _list) return;
    _list->remove(a);
}

slope() [1/2]

double TLine2D::slope ( double  a )

inline

Definition at line 94 of file TLine2D.h.

                       {
    return _slope = a;
}

slope() [2/2]

double TLine2D::slope ( void  ) const

inline

Definition at line 76 of file TLine2D.h.

                         {
    return _slope;
}

xOffset()

double TLine2D::xOffset ( void  ) const

inline

Definition at line 88 of file TLine2D.h.

                           {
    return - _yOffset / _slope;
}

yOffset() [1/2]

double TLine2D::yOffset ( double  a )

inline

Definition at line 100 of file TLine2D.h.

                         {
    return _yOffset = a;
}

yOffset() [2/2]

double TLine2D::yOffset ( void  ) const

inline

Definition at line 82 of file TLine2D.h.

                           {
    return _yOffset;
}

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

• TLine2D.h
• TLine2D.cxx