Tesseract: LLSQ Class Reference

LLSQ::LLSQ ( ) [inline]

Definition at line 40 of file linlsq.h.

References clear().

00040            {  //constructor
00041       clear();  //set to zeros
00042     }

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

Add an element to the accumulator.

Definition at line 57 of file linlsq.cpp.

References n, sigx, sigxx, sigxy, sigy, and sigyy.

Referenced by PDLSQ::add(), and WERD::baseline_normalise_x().

00060                 {
00061   n++;                           //count elements
00062   sigx += x;                     //update accumulators
00063   sigy += y;
00064   sigxx += x * x;
00065   sigxy += x * y;
00066   sigyy += y * y;
00067 }

double LLSQ::c ( double m )

Get constant

Return the constant of the line fit.

Definition at line 107 of file linlsq.cpp.

References n, sigx, and sigy.

Referenced by WERD::baseline_normalise_x().

00109                 {
00110   if (n > 0)
00111     return (sigy - m * sigx) / n;
00112   else
00113     return 0;                    //too little
00114 }

void LLSQ::clear ( )

Function to initialize a LLSQ.

Definition at line 44 of file linlsq.cpp.

References n, sigx, sigxx, sigxy, sigy, and sigyy.

Referenced by PDLSQ::clear(), and LLSQ().

00044                  {  //initialize
00045   n = 0;                         //no elements
00046   sigx = 0;                      //update accumulators
00047   sigy = 0;
00048   sigxx = 0;
00049   sigxy = 0;
00050   sigyy = 0;
00051 }

INT32 LLSQ::count ( ) [inline]

Definition at line 51 of file linlsq.h.

References n.

Referenced by WERD::baseline_normalise_x(), and PDLSQ::count().

00051                   {  //no of elements
00052       return n;
00053     }

double LLSQ::m ( )

Get gradient

Return the gradient of the line fit.

Definition at line 94 of file linlsq.cpp.

References n, sigx, sigxx, sigxy, and sigy.

Referenced by WERD::baseline_normalise_x().

00094                {  //get gradient
00095   if (n > 1)
00096     return (sigxy - sigx * sigy / n) / (sigxx - sigx * sigx / n);
00097   else
00098     return 0;                    //too little
00099 }

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

Delete an element from the acculuator.

Definition at line 73 of file linlsq.cpp.

References ABORT, EMPTY_LLSQ, ERRCODE::error(), n, NULL, sigx, sigxx, sigxy, sigy, and sigyy.

Referenced by PDLSQ::remove().

00076                    {
00077   if (n <= 0)
00078                                  //illegal
00079     EMPTY_LLSQ.error ("LLSQ::remove", ABORT, NULL);
00080   n--;                           //count elements
00081   sigx -= x;                     //update accumulators
00082   sigy -= y;
00083   sigxx -= x * x;
00084   sigxy -= x * y;
00085   sigyy -= y * y;
00086 }

double LLSQ::rms	(	double	m,
		double	c
	)

Get Error

Return the rms error of the fit.

Definition at line 122 of file linlsq.cpp.

References n, sigx, sigxx, sigxy, sigy, and sigyy.

00125                   {
00126   double error;                  //total error
00127 
00128   if (n > 0) {
00129     error =
00130       sigyy + m * (m * sigxx + 2 * (c * sigx - sigxy)) + c * (n * c -
00131       2 * sigy);
00132     if (error >= 0)
00133       error = sqrt (error / n);  //sqrt of mean
00134     else
00135       error = 0;
00136   }
00137   else
00138     error = 0;                   //too little
00139   return error;
00140 }

double LLSQ::spearman ( )

Get error

Return the spearman correlation coefficient.

Definition at line 148 of file linlsq.cpp.

References n, sigx, sigxx, sigxy, sigy, and sigyy.

00148                       {  //get error
00149   double error;                  //total error
00150 
00151   if (n > 1) {
00152     error = (sigxx - sigx * sigx / n) * (sigyy - sigy * sigy / n);
00153     if (error > 0) {
00154       error = (sigxy - sigx * sigy / n) / sqrt (error);
00155     }
00156     else
00157       error = 1;
00158   }
00159   else
00160     error = 1;                   //too little
00161   return error;
00162 }