ossimLeastSquaresPlane Class Reference

Provide 2D Least Squares Plane model fitting The math model is that of a plane of the form: More...

#include <ossimLeastSquaresPlane.h>

Public Member Functions
	ossimLeastSquaresPlane (const ossimLeastSquaresPlane &)
	ossimLeastSquaresPlane ()
	Instantiate as zero surface. More...
ossimLeastSquaresPlane &	operator= (const ossimLeastSquaresPlane &)
virtual	~ossimLeastSquaresPlane ()
	Free internal storage. More...
virtual void	clear ()
	Will clear everything and set it up to for another solve. More...
virtual void	addSample (double x, double y, double z_mea)
	add a single data sample. More...
virtual bool	getLSParms (double &pa, double &pb, double &pc) const
	return LS solution parameters. More...
virtual void	setLSParams (double pa, double pb, double pc)
virtual double	lsFitValue (double xx, double yy) const
	interpolate LS-fit value at location (xx,yy) - returns z(xx,yy). More...
bool	solveLS ()
	compute least squares parameter solution - true if succesfull. More...

Private Attributes
double	m_a
	linear-X term. More...
double	m_b
	linear-Y term. More...
double	m_c
	constant term. More...
NEWMAT::Matrix *	AtA
	Normal system coefficient matrix. More...
NEWMAT::Matrix *	Atb
	Normal system RHS vector. More...
ossim_uint32	m_numSamples

Detailed Description

Provide 2D Least Squares Plane model fitting The math model is that of a plane of the form:

z(x,y) = ax + b*y + c

The getLSParms() method returns parameter values which are the least squares solution associated with the samples added via addSample(). Note that it is necessary to add at least three sample to obtain a solution.

Definition at line 27 of file ossimLeastSquaresPlane.h.

Constructor & Destructor Documentation

ossimLeastSquaresPlane() [1/2]

ossimLeastSquaresPlane::ossimLeastSquaresPlane

(

const ossimLeastSquaresPlane &

rhs

)

Definition at line 35 of file ossimLeastSquaresPlane.cpp.

References AtA, Atb, m_a, m_b, and m_c.

{
   // allocate normal system accumulation matrices
   AtA = new NEWMAT::Matrix(3,3);
   Atb = new NEWMAT::Matrix(3,1);

   m_a = rhs.m_a;
   m_b = rhs.m_b;
   m_c = rhs.m_c;
   
   *AtA  = *rhs.AtA;
   *Atb  = *rhs.Atb;
}

ossimLeastSquaresPlane() [2/2]

ossimLeastSquaresPlane::ossimLeastSquaresPlane

(

)

Instantiate as zero surface.

Definition at line 16 of file ossimLeastSquaresPlane.cpp.

References AtA, and Atb.

: m_a(0.0),
  m_b(0.0),
  m_c(0.0),
  AtA(NULL),
  Atb(NULL),
  m_numSamples(0)
{
   // allocate normal system accumulation matrices
   AtA = new NEWMAT::Matrix(3,3);
   Atb = new NEWMAT::Matrix(3,1);
   
   // ensure initilization to zero
   *AtA = 0.0;
   *Atb = 0.0;
   
   return;
}

~ossimLeastSquaresPlane()

ossimLeastSquaresPlane::~ossimLeastSquaresPlane ( )

virtual

Free internal storage.

Definition at line 49 of file ossimLeastSquaresPlane.cpp.

References AtA, and Atb.

{
   if(AtA)
   {
      delete AtA;
      AtA = NULL;
   }
   if(Atb)
   {
      delete Atb;
      Atb = NULL;
   }
}

Member Function Documentation

addSample()

void ossimLeastSquaresPlane::addSample ( double  x, double  y, double  z_mea  )

virtual

add a single data sample.

Parameters

x	coordinate of sample location.
y	coordinate of sample location.
zmea	sample value measured at (x,y)

Definition at line 83 of file ossimLeastSquaresPlane.cpp.

References AtA, Atb, and m_numSamples.

{
   // form normal system layer
   NEWMAT::Matrix AtA_layer(3,1);
   AtA_layer(1,1) = xx;
   AtA_layer(2,1) = yy;
   AtA_layer(3,1) = 1.0;
   
   // accumulate layer into normal system
   *AtA += AtA_layer * AtA_layer.t();
   *Atb += AtA_layer * zmea;

   ++m_numSamples;
}

clear()

void ossimLeastSquaresPlane::clear ( )

virtual

Will clear everything and set it up to for another solve.

Just add points and call the solve method.

Definition at line 74 of file ossimLeastSquaresPlane.cpp.

References AtA, Atb, m_a, m_b, and m_c.

{
   *AtA    = 0.0;
   *Atb    = 0.0;  
   m_a    = 0.0;
   m_b    = 0.0;
   m_c    = 0.0;
}

getLSParms()

bool ossimLeastSquaresPlane::getLSParms ( double &  pa, double &  pb, double &  pc  ) const

virtual

return LS solution parameters.

Parameters

pa	set to x coefficient.
pb	set to y coefficient
pc	set to constant term

Definition at line 112 of file ossimLeastSquaresPlane.cpp.

References m_a, m_b, and m_c.

{
   pa = m_a;
   pb = m_b;
   pc = m_c;
   
   return true;
}

lsFitValue()

virtual double ossimLeastSquaresPlane::lsFitValue ( double  xx, double  yy  ) const

inlinevirtual

interpolate LS-fit value at location (xx,yy) - returns z(xx,yy).

Parameters

xx	"x" coordinate at which to interpolate.
yy	"y" "y" coordinate at which to interpolate.

Definition at line 83 of file ossimLeastSquaresPlane.h.

{ return (m_a*xx + m_b*yy + m_c); }

operator=()

ossimLeastSquaresPlane & ossimLeastSquaresPlane::operator=

(

const ossimLeastSquaresPlane &

rhs

)

Definition at line 62 of file ossimLeastSquaresPlane.cpp.

References AtA, Atb, m_a, m_b, and m_c.

{
   m_a    = rhs.m_a;
   m_b    = rhs.m_b;
   m_c    = rhs.m_c;
   
   *AtA    = *rhs.AtA;
   *Atb    = *rhs.Atb;
   
   return *this;
}

setLSParams()

void ossimLeastSquaresPlane::setLSParams ( double  pa, double  pb, double  pc  )

virtual

Parameters

pa	set to x coefficient.
pb	set to y coefficient
pc	set to constant term

Definition at line 121 of file ossimLeastSquaresPlane.cpp.

References m_a, m_b, and m_c.

{
   m_a = pa;
   m_b = pb;
   m_c = pc;
}

solveLS()

bool ossimLeastSquaresPlane::solveLS

(

)

compute least squares parameter solution - true if succesfull.

Definition at line 98 of file ossimLeastSquaresPlane.cpp.

References AtA, m_a, m_b, m_c, and m_numSamples.

{
   if (m_numSamples < 3)
      return false;

   NEWMAT::Matrix Soln(3,1);
   Soln = AtA->i() * (*Atb);
   m_a = Soln(1,1);
   m_b = Soln(2,1);
   m_c = Soln(3,1);
   
   return true;
}

Member Data Documentation

AtA

NEWMAT::Matrix* ossimLeastSquaresPlane::AtA

private

Normal system coefficient matrix.

Definition at line 110 of file ossimLeastSquaresPlane.h.

Referenced by addSample(), clear(), operator=(), ossimLeastSquaresPlane(), solveLS(), and ~ossimLeastSquaresPlane().

Atb

NEWMAT::Matrix* ossimLeastSquaresPlane::Atb

private

Normal system RHS vector.

Definition at line 115 of file ossimLeastSquaresPlane.h.

Referenced by addSample(), clear(), operator=(), ossimLeastSquaresPlane(), and ~ossimLeastSquaresPlane().

m_a

double ossimLeastSquaresPlane::m_a

private

linear-X term.

Definition at line 95 of file ossimLeastSquaresPlane.h.

Referenced by clear(), getLSParms(), operator=(), ossimLeastSquaresPlane(), setLSParams(), and solveLS().

m_b

double ossimLeastSquaresPlane::m_b

private

linear-Y term.

Definition at line 100 of file ossimLeastSquaresPlane.h.

Referenced by clear(), getLSParms(), operator=(), ossimLeastSquaresPlane(), setLSParams(), and solveLS().

m_c

double ossimLeastSquaresPlane::m_c

private

constant term.

Definition at line 105 of file ossimLeastSquaresPlane.h.

Referenced by clear(), getLSParms(), operator=(), ossimLeastSquaresPlane(), setLSParams(), and solveLS().

m_numSamples

ossim_uint32 ossimLeastSquaresPlane::m_numSamples

private

Definition at line 117 of file ossimLeastSquaresPlane.h.

Referenced by addSample(), and solveLS().

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

• ossimLeastSquaresPlane.h
• ossimLeastSquaresPlane.cpp