QLSQ Class Reference

#include <quadlsq.h>

Public Member Functions
	QLSQ ()
void	clear ()
void	add (double x, double y)
void	remove (double x, double y)
inT32	count ()
void	fit (int degree)
double	get_a ()
double	get_b ()
double	get_c ()

Detailed Description

Definition at line 25 of file quadlsq.h.

Constructor & Destructor Documentation

QLSQ::QLSQ ( )

inline

Definition at line 28 of file quadlsq.h.

           {  //constructor
      clear();  //set to zeros
    }

Member Function Documentation

void QLSQ::add	(	double	x,
		double	y
	)

Definition at line 58 of file quadlsq.cpp.

                {
  n++;                           //count elements
  sigx += x;                     //update accumulators
  sigy += y;
  sigxx += x * x;
  sigxy += x * y;
  sigyy += y * y;
  sigxxx += (long double) x *x * x;
  sigxxy += (long double) x *x * y;
  sigxxxx += (long double) x *x * x * x;
}

void QLSQ::clear

(

)

Definition at line 36 of file quadlsq.cpp.

                 {  //initialize
  a = 0;
  b = 0;
  c = 0;
  n = 0;                         //no elements
  sigx = 0;                      //update accumulators
  sigy = 0;
  sigxx = 0;
  sigxy = 0;
  sigyy = 0;
  sigxxx = 0;
  sigxxy = 0;
  sigxxxx = 0;
}

inT32 QLSQ::count ( )

inline

Definition at line 39 of file quadlsq.h.

                  {  //no of elements
      return n;
    }

void QLSQ::fit

(

int

degree

)

Definition at line 105 of file quadlsq.cpp.

                {
  long double cubetemp;          //intermediates
  long double squaretemp;
  long double top96, bottom96;   /*accurate top & bottom */

  if (n >= 4 && degree >= 2) {
    cubetemp = sigxxx * n - (long double) sigxx *sigx;

    top96 =
      cubetemp * ((long double) sigxy * n - (long double) sigx * sigy);

    squaretemp = (long double) sigxx *n - (long double) sigx *sigx;

    top96 += squaretemp * ((long double) sigxx * sigy - sigxxy * n);

    bottom96 = cubetemp * cubetemp;

    bottom96 -= squaretemp * (sigxxxx * n - (long double) sigxx * sigxx);

    a = top96 / bottom96;

    top96 = ((long double) sigxx * sigx - sigxxx * n) * a
      + (long double) sigxy *n - (long double) sigx *sigy;
    bottom96 = (long double) sigxx *n - (long double) sigx *sigx;
    b = top96 / bottom96;

    c = (sigy - a * sigxx - b * sigx) / n;
  }
  else if (n == 0 || degree < 0) {
    a = b = c = 0;
  }
  else {
    a = 0;
    if (n > 1 && degree > 0) {
      b = (sigxy * n - sigx * sigy) / (sigxx * n - sigx * sigx);
    }
    else
      b = 0;
    c = (sigy - b * sigx) / n;
  }
}

double QLSQ::get_a ( )

inline

Definition at line 45 of file quadlsq.h.

                   {  //get x squard
      return a;
    }

double QLSQ::get_b ( )

inline

Definition at line 48 of file quadlsq.h.

                   {  //get x squard
      return b;
    }

double QLSQ::get_c ( )

inline

Definition at line 51 of file quadlsq.h.

                   {  //get x squard
      return c;
    }

void QLSQ::remove	(	double	x,
		double	y
	)

Definition at line 80 of file quadlsq.cpp.

                   {
  if (n <= 0)
                                 //illegal
    EMPTY_QLSQ.error ("QLSQ::remove", ABORT, NULL);
  n--;                           //count elements
  sigx -= x;                     //update accumulators
  sigy -= y;
  sigxx -= x * x;
  sigxy -= x * y;
  sigyy -= y * y;
  sigxxx -= (long double) x *x * x;
  sigxxy -= (long double) x *x * y;
  sigxxxx -= (long double) x *x * x * x;
}

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

• /home/abuild/rpmbuild/BUILD/tesseract-ocr-3.02.02/ccstruct/quadlsq.h
• /home/abuild/rpmbuild/BUILD/tesseract-ocr-3.02.02/ccstruct/quadlsq.cpp