ossimLeastSquaresBilin Class Reference

Provide 2D Least Squares Bilinear model fitting The math model is that of a bilinear surface of the form: More...

#include <ossimLeastSquaresBilin.h>

Public Member Functions
	ossimLeastSquaresBilin (const ossimLeastSquaresBilin &)
	ossimLeastSquaresBilin ()
	Instantiate as zero surface. More...
ossimLeastSquaresBilin &	operator= (const ossimLeastSquaresBilin &)
virtual	~ossimLeastSquaresBilin ()
	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 yy, double zmea)
	add a single data sample. More...
virtual bool	getLSParms (double &pa, double &pb_x, double &pc_y, double &pd_xy) const
	return LS solution parameters. More...
virtual void	setLSParams (double pa, double pb_x, double pc_y, double pd_xy)
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	bl_a
	constant term. More...
double	bl_b
	linear-X term. More...
double	bl_c
	linear-Y term. More...
double	bl_d
	cross-XY term More...
NEWMAT::Matrix *	AtA
	Normal system coefficient matrix. More...
NEWMAT::Matrix *	Atb
	Normal system RHS vector. More...

Detailed Description

Provide 2D Least Squares Bilinear model fitting The math model is that of a bilinear surface of the form:

z(x,y) = a + b*x + c*y + d*x*y

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 four sample to obtain a solution.

Definition at line 27 of file ossimLeastSquaresBilin.h.

Constructor & Destructor Documentation

ossimLeastSquaresBilin() [1/2]

ossimLeastSquaresBilin::ossimLeastSquaresBilin

(

const ossimLeastSquaresBilin &

rhs

)

Definition at line 34 of file ossimLeastSquaresBilin.cpp.

References AtA, Atb, bl_a, bl_b, bl_c, and bl_d.

{
   // allocate normal system accumulation matrices
   AtA = new NEWMAT::Matrix(4,4);
   Atb = new NEWMAT::Matrix(4,1);

   bl_a = rhs.bl_a;
   bl_b = rhs.bl_b;
   bl_c = rhs.bl_c;
   bl_d = rhs.bl_d;
   
   *AtA  = *rhs.AtA;
   *Atb  = *rhs.Atb;
}

ossimLeastSquaresBilin() [2/2]

ossimLeastSquaresBilin::ossimLeastSquaresBilin

(

)

Instantiate as zero surface.

Definition at line 16 of file ossimLeastSquaresBilin.cpp.

References AtA, and Atb.

    : bl_a(0.0)
    , bl_b(0.0)
    , bl_c(0.0)
    , bl_d(0.0)
    , AtA(NULL)
    , Atb(NULL)
{
   // allocate normal system accumulation matrices
   AtA = new NEWMAT::Matrix(4,4);
   Atb = new NEWMAT::Matrix(4,1);
   
   // ensure initilization to zero
   *AtA = 0.0;
   *Atb = 0.0;
   
   return;
}

~ossimLeastSquaresBilin()

ossimLeastSquaresBilin::~ossimLeastSquaresBilin ( )

virtual

Free internal storage.

Definition at line 49 of file ossimLeastSquaresBilin.cpp.

References AtA, and Atb.

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

Member Function Documentation

addSample()

void ossimLeastSquaresBilin::addSample ( double  x, double  yy, double  zmea  )

virtual

add a single data sample.

Parameters

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

Definition at line 85 of file ossimLeastSquaresBilin.cpp.

References AtA, and Atb.

Referenced by ossimBilinearProjection::initializeBilinear(), ossim2dBilinearTransform::setFromPoints(), and ossim2dTo2dMatrixTransform::setFromPoints().

{
   // form normal system layer
   NEWMAT::Matrix AtA_layer(4,1);
   AtA_layer(1,1) = 1.0;
   AtA_layer(2,1) = xx;
   AtA_layer(3,1) = yy;
   AtA_layer(4,1) = xx*yy;
   
   // accumulate layer into normal system
   *AtA += AtA_layer * AtA_layer.t();
   *Atb += AtA_layer * zmea;
   
}

clear()

void ossimLeastSquaresBilin::clear ( )

virtual

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

Just add points and call the solve method.

Definition at line 75 of file ossimLeastSquaresBilin.cpp.

References AtA, Atb, bl_a, bl_b, bl_c, and bl_d.

Referenced by ossimBilinearProjection::initializeBilinear().

{
   *AtA    = 0.0;
   *Atb    = 0.0;  
   bl_a    = 0.0;
   bl_b    = 0.0;
   bl_c    = 0.0;
   bl_d    = 0.0;
}

getLSParms()

bool ossimLeastSquaresBilin::getLSParms ( double &  pa, double &  pb_x, double &  pc_y, double &  pd_xy  ) const

virtual

return LS solution parameters.

Parameters

pa	set to constant coefficient.
pb_x	set to linear coefficient of "x"
pc_y	set to linear coefficient of "y"
pd_xy	set to cross coefficient of "x*y"

Definition at line 113 of file ossimLeastSquaresBilin.cpp.

References bl_a, bl_b, bl_c, and bl_d.

Referenced by ossim2dBilinearTransform::setFromPoints(), and ossim2dTo2dMatrixTransform::setFromPoints().

{
   pa    = bl_a;
   pb_x  = bl_b;
   pc_y  = bl_c;
   pd_xy = bl_d;
   
   return true;
}

lsFitValue()

virtual double ossimLeastSquaresBilin::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 89 of file ossimLeastSquaresBilin.h.

Referenced by ossimBilinearProjection::lineSampleHeightToWorld(), ossimBilinearProjection::setTiePoints(), and ossimBilinearProjection::worldToLineSample().

      {
         return (bl_a + bl_b*xx + bl_c*yy + bl_d*xx*yy);
      }

operator=()

ossimLeastSquaresBilin & ossimLeastSquaresBilin::operator=

(

const ossimLeastSquaresBilin &

rhs

)

Definition at line 62 of file ossimLeastSquaresBilin.cpp.

References AtA, Atb, bl_a, bl_b, bl_c, and bl_d.

{
   bl_a    = rhs.bl_a;
   bl_b    = rhs.bl_b;
   bl_c    = rhs.bl_c;
   bl_d    = rhs.bl_d;
   
   *AtA    = *rhs.AtA;
   *Atb    = *rhs.Atb;
   
   return *this;
}

setLSParams()

void ossimLeastSquaresBilin::setLSParams ( double  pa, double  pb_x, double  pc_y, double  pd_xy  )

virtual

Parameters

pa	set to constant coefficient.
pb_x	set to linear coefficient of "x"
pc_y	set to linear coefficient of "y"
pd_xy	set to cross coefficient of "x*y"

Definition at line 126 of file ossimLeastSquaresBilin.cpp.

References bl_a, bl_b, bl_c, and bl_d.

{
   bl_a = pa;
   bl_b = pb_x;
   bl_c = pc_y;
   bl_d = pd_xy;
}

solveLS()

bool ossimLeastSquaresBilin::solveLS

(

)

compute least squares parameter solution - true if succesfull.

Definition at line 100 of file ossimLeastSquaresBilin.cpp.

References AtA, bl_a, bl_b, bl_c, and bl_d.

Referenced by ossimBilinearProjection::initializeBilinear(), ossim2dBilinearTransform::setFromPoints(), and ossim2dTo2dMatrixTransform::setFromPoints().

{
   NEWMAT::Matrix Soln(4,1);
   Soln = AtA->i() * (*Atb);
   bl_a = Soln(1,1);
   bl_b = Soln(2,1);
   bl_c = Soln(3,1);
   bl_d = Soln(4,1);
   
   
   return true;
}

Member Data Documentation

AtA

NEWMAT::Matrix* ossimLeastSquaresBilin::AtA

private

Normal system coefficient matrix.

Definition at line 123 of file ossimLeastSquaresBilin.h.

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

Atb

NEWMAT::Matrix* ossimLeastSquaresBilin::Atb

private

Normal system RHS vector.

Definition at line 128 of file ossimLeastSquaresBilin.h.

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

bl_a

double ossimLeastSquaresBilin::bl_a

private

constant term.

Definition at line 103 of file ossimLeastSquaresBilin.h.

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

bl_b

double ossimLeastSquaresBilin::bl_b

private

linear-X term.

Definition at line 108 of file ossimLeastSquaresBilin.h.

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

bl_c

double ossimLeastSquaresBilin::bl_c

private

linear-Y term.

Definition at line 113 of file ossimLeastSquaresBilin.h.

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

bl_d

double ossimLeastSquaresBilin::bl_d

private

cross-XY term

Definition at line 118 of file ossimLeastSquaresBilin.h.

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

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

• ossimLeastSquaresBilin.h
• ossimLeastSquaresBilin.cpp