Tesseract: QLSQ Class Reference

QLSQ::QLSQ ( ) [inline]

Definition at line 32 of file quadlsq.h.

References clear().

00032            {  //constructor
00033       clear();  //set to zeros
00034     }

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

Add an element to the accumulator.

Definition at line 52 of file quadlsq.cpp.

References n, sigx, sigxx, sigxxx, sigxxxx, sigxxy, sigxy, sigy, and sigyy.

Referenced by merge_oldbl_parts(), and QSPLINE::QSPLINE().

00055                 {
00056   n++;                           //count elements
00057   sigx += x;                     //update accumulators
00058   sigy += y;
00059   sigxx += x * x;
00060   sigxy += x * y;
00061   sigyy += y * y;
00062   sigxxx += (long double) x *x * x;
00063   sigxxy += (long double) x *x * y;
00064   sigxxxx += (long double) x *x * x * x;
00065 }

void QLSQ::clear ( )

Function to initialize a QLSQ.

Definition at line 33 of file quadlsq.cpp.

References a, b, c, n, sigx, sigxx, sigxxx, sigxxxx, sigxxy, sigxy, sigy, and sigyy.

Referenced by merge_oldbl_parts(), QLSQ(), and QSPLINE::QSPLINE().

00033                  {  //initialize
00034   a = 0;
00035   b = 0;
00036   c = 0;
00037   n = 0;                         //no elements
00038   sigx = 0;                      //update accumulators
00039   sigy = 0;
00040   sigxx = 0;
00041   sigxy = 0;
00042   sigyy = 0;
00043   sigxxx = 0;
00044   sigxxy = 0;
00045   sigxxxx = 0;
00046 }

INT32 QLSQ::count ( ) [inline]

Definition at line 43 of file quadlsq.h.

References n.

00043                   {  //no of elements
00044       return n;
00045     }

void QLSQ::fit ( int degree )

Fit the given degree of polynomial and store the result.

Definition at line 93 of file quadlsq.cpp.

References a, b, c, n, sigx, sigxx, sigxxx, sigxxxx, sigxxy, sigxy, and sigy.

Referenced by merge_oldbl_parts(), and QSPLINE::QSPLINE().

00095                 {
00096   long double cubetemp;          //intermediates
00097   long double squaretemp;
00098   long double top96, bottom96;   /*accurate top & bottom */
00099 
00100   if (n >= 4 && degree >= 2) {
00101     cubetemp = sigxxx * n - (long double) sigxx *sigx;
00102 
00103     top96 =
00104       cubetemp * ((long double) sigxy * n - (long double) sigx * sigy);
00105 
00106     squaretemp = (long double) sigxx *n - (long double) sigx *sigx;
00107 
00108     top96 += squaretemp * ((long double) sigxx * sigy - sigxxy * n);
00109 
00110     bottom96 = cubetemp * cubetemp;
00111 
00112     bottom96 -= squaretemp * (sigxxxx * n - (long double) sigxx * sigxx);
00113 
00114     a = top96 / bottom96;
00115 
00116     top96 = ((long double) sigxx * sigx - sigxxx * n) * a
00117       + (long double) sigxy *n - (long double) sigx *sigy;
00118     bottom96 = (long double) sigxx *n - (long double) sigx *sigx;
00119     b = top96 / bottom96;
00120 
00121     c = (sigy - a * sigxx - b * sigx) / n;
00122   }
00123   else if (n == 0 || degree < 0) {
00124     a = b = c = 0;
00125   }
00126   else {
00127     a = 0;
00128     if (n > 1 && degree > 0) {
00129       b = (sigxy * n - sigx * sigy) / (sigxx * n - sigx * sigx);
00130     }
00131     else
00132       b = 0;
00133     c = (sigy - b * sigx) / n;
00134   }
00135 }

double QLSQ::get_a ( ) [inline]

Definition at line 49 of file quadlsq.h.

References a.

Referenced by QSPLINE::QSPLINE().

00049                    {  //get x squard
00050       return a;
00051     }

double QLSQ::get_b ( ) [inline]

Definition at line 52 of file quadlsq.h.

References b.

Referenced by merge_oldbl_parts(), and QSPLINE::QSPLINE().

00052                    {  //get x squard
00053       return b;
00054     }

double QLSQ::get_c ( ) [inline]

Definition at line 55 of file quadlsq.h.

References c.

Referenced by merge_oldbl_parts(), and QSPLINE::QSPLINE().

00055                    {  //get x squard
00056       return c;
00057     }

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

Delete an element from the acculuator.

Definition at line 71 of file quadlsq.cpp.

References ABORT, EMPTY_QLSQ, ERRCODE::error(), n, NULL, sigx, sigxx, sigxxx, sigxxxx, sigxxy, sigxy, sigy, and sigyy.

00074                    {
00075   if (n <= 0)
00076                                  //illegal
00077     EMPTY_QLSQ.error ("QLSQ::remove", ABORT, NULL);
00078   n--;                           //count elements
00079   sigx -= x;                     //update accumulators
00080   sigy -= y;
00081   sigxx -= x * x;
00082   sigxy -= x * y;
00083   sigyy -= y * y;
00084   sigxxx -= (long double) x *x * x;
00085   sigxxy -= (long double) x *x * y;
00086   sigxxxx -= (long double) x *x * x * x;
00087 }