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LinearSums2dC::LinearSums2dC(void) LinearSums2dC::LinearSums2dC(const LinearSums2dC &) LinearSums2dC::SetZero(void) LinearSums2dC::operator+=(const Point2dC &) LinearSums2dC::operator-=(const Point2dC &) LinearSums2dC::Add(const RealT,const RealT) LinearSums2dC::Remove(const RealT,const RealT) LinearSums2dC::N(void) const LinearSums2dC::MeanX(void) const LinearSums2dC::MeanY(void) const LinearSums2dC::VarX(void) const LinearSums2dC::VarY(void) const LinearSums2dC::Centroid(void) const LinearSums2dC::SlopeY(void) const LinearSums2dC::SlopeX(void) const LinearSums2dC::InterceptY(void) const LinearSums2dC::InterceptX(void) const LinearSums2dC::Angle(void) const LinearSums2dC::LineABCy(void) const LinearSums2dC::LineABCx(void) const LinearSums2dC::UseLineABCx(void) const LinearSums2dC::LineABCxy(void) const LinearSums2dC::MinimumVolume(void) const LinearSums2dC::Correlation(void) const LinearSums2dC::operator<<(ostream &,const LinearSums2dC &) LinearSums2dC::operator>>(istream &,LinearSums2dC &) LinearSums2dC::Add(const LinearSums2dC::RealT,const LinearSums2dC::RealT) LinearSums2dC::Remove(const LinearSums2dC::RealT,const LinearSums2dC::RealT)

LinearSums2dC
The class LinearSums2dC serves for computation of linear dependences in 2D space.
include	"amma/LinearS2.hh"
User Level:	Default
Library:	Mag2
Example:	exMat2d.cc
Section:	Geometry.2-D
In Scope:	std

Typedefs:

typedef StdTypeC::RealT RealT;

LongIntT n;

RealT sumX;

RealT sumY;

RealT sumXX;

RealT sumXY;

RealT sumYY;

LinearSums2dC()

The zero sums.

LinearSums2dC(const LinearSums2dC & sums)

Copy constructor.
Updating. ---------

void SetZero()

Initializies the sums.

const LinearSums2dC & operator+=(const Point2dC & p)

Adds another point to the sums.

const LinearSums2dC & operator-=(const Point2dC & p)

Subtracts the point from the sums.

const LinearSums2dC & Add(const RealT x,const RealT y)

Adds another point to the sums.

const LinearSums2dC & Remove(const RealT x,const RealT y)

Removes the point from the sums.
Computation of statistics. --------------------------

LongIntT N() const

Returns the number of data have been entered into the sums.

RealT MeanX() const

Returns the mean value of the x.

RealT MeanY() const

Returns the mean value of the y.

RealT VarX() const

Returns the variance of the x.

RealT VarY() const

Returns the variance of the y.

Point2dC Centroid() const

Returns the point with the mininum distance from this set of points.
The used criterion is Sum((Y-y)^2+(X-x)^2) -> min.

RealT SlopeY() const

Returns the slope dY/dX. The used criterion is Sum(Y-y)^2 -> min.
It means dY/dX = k, where y = k*x+q.

RealT SlopeX() const

Returns the slope dX/dY. The used criterion is Sum(X-x)^2 -> min.
It means dX/dY = k, where x = k*y+q.

RealT InterceptY() const

Returns the estimate of q, if y = k*x+q.
The used criterion is Sum(Y-y)^2 -> min.

RealT InterceptX() const

Returns the estimate of q, if y = k*y+q.
The used criterion is Sum(X-x)^2 -> min.

RealT Angle() const

If points form a line, estimate its angle.
Returns an angle in randians.

LineABC2dC LineABCy() const

Returns the equation of the line. The used criterion is
Sum(Y-y)^2 -> min.

LineABC2dC LineABCx() const

Returns the equation of the line. The used criterion is
Sum(X-x)^2 -> min.

BooleanT UseLineABCx() const

Which is better LineABCx() or LineABCy ?

LineABC2dC LineABCxy() const

Return the best fit of LineABCx, LineABCy.
This may change to Sum(Y-y)^2 + Sum(X-x)^2 -> min in the future.

RealT MinimumVolume() const

Returns the determinant of the centralized covariance matrix.
The determinant is propotional to the volume of the minimum elipsoid containing data.

RealT Correlation() const

Returns the value of the correlation between X and Y.

ostream & operator<<(ostream & outS,const LinearSums2dC & sums)

istream & operator>>(istream & inS,LinearSums2dC & sums)

const LinearSums2dC & Add(const LinearSums2dC::RealT x,const LinearSums2dC::RealT y)

const LinearSums2dC & Remove(const LinearSums2dC::RealT x,const LinearSums2dC::RealT y)