lsst::jointcal::AstrometryTransformLinearShift Class Reference

just here to provide a specialized constructor, and fit. More...

#include <AstrometryTransform.h>

Inheritance diagram for lsst::jointcal::AstrometryTransformLinearShift:

Public Member Functions
	AstrometryTransformLinearShift (double ox=0., double oy=0.)
	Add ox and oy.
	AstrometryTransformLinearShift (Point const &point)
double	fit (StarMatchList const &starMatchList)
	fits a transform to a std::list of Point pairs (p1,p2, the Point fields in StarMatch).
std::size_t	getNpar () const
	returns the number of parameters (to compute chi2's)
virtual void	apply (double xIn, double yIn, double &xOut, double &yOut) const=0
void	apply (Point const &in, Point &out) const
	applies the tranfo to in and writes into out. Is indeed virtual.
Point	apply (Point const &in) const
	All these apply(..) shadow the virtual one in derived classes, unless one writes "using AstrometryTransform::apply".
Frame	apply (Frame const &inputframe, bool inscribed) const
	Transform a bounding box, taking either the inscribed or circumscribed box.
AstrometryTransformLinear	operator* (AstrometryTransformLinear const &right) const
	enables to combine linear tranformations: T1=T2*T3 is legal.
AstrometryTransformPolynomial	operator* (AstrometryTransformPolynomial const &right) const
	Composition (internal stuff in quadruple precision)
AstrometryTransformLinear	inverted () const
	returns the inverse: T1 = T2.inverted();
void	print (std::ostream &out) const override
	prints the transform coefficients to stream.
void	computeDerivative (Point const &where, AstrometryTransformLinear &derivative, double step=0.01) const override
	Computes the local Derivative of a transform, w.r.t.
AstrometryTransformLinear	linearApproximation (Point const &where, double step=0.01) const override
	linear (local) approximation.
std::unique_ptr< AstrometryTransform >	clone () const override
	returns a copy (allocated by new) of the transformation.
std::unique_ptr< AstrometryTransform >	inverseTransform (double precision, const Frame &region) const override
	returns an inverse transform. Numerical if not overloaded.
double	A11 () const
double	A12 () const
double	A21 () const
double	A22 () const
double	Dx () const
double	Dy () const
std::size_t	getOrder () const
	Returns the polynomial order.
virtual void	transformPosAndErrors (const FatPoint &in, FatPoint &out) const override
	a mix of apply and Derivative
AstrometryTransformPolynomial	operator+ (AstrometryTransformPolynomial const &right) const
	Addition.
AstrometryTransformPolynomial	operator- (AstrometryTransformPolynomial const &right) const
	Subtraction.
std::unique_ptr< AstrometryTransform >	composeAndReduce (AstrometryTransformPolynomial const &right) const
	Return a reduced composition of newTransform = this(right()), or nullptr if it cannot be reduced.
virtual std::unique_ptr< AstrometryTransform >	composeAndReduce (AstrometryTransform const &right) const
	Return a reduced composition of newTransform = this(right()), or nullptr if it cannot be reduced.
double	coeffOrZero (std::size_t powX, std::size_t powY, std::size_t whichCoord) const
	read access, zero if beyond order
double	determinant () const
double	paramRef (Eigen::Index i) const override
double &	paramRef (Eigen::Index i) override
void	paramDerivatives (Point const &where, double *dx, double *dy) const override
	Derivative w.r.t parameters.
std::shared_ptr< ast::Mapping >	toAstMap (jointcal::Frame const &domain) const override
	Create an equivalent AST mapping for this transformation, including an analytic inverse if possible.
void	write (std::ostream &s) const override
void	write (const std::string &fileName) const
void	read (std::istream &s)
std::string	__str__ () const
void	transformStar (FatPoint &in) const
virtual double	getJacobian (Point const &point) const
	returns the local jacobian.
virtual double	getJacobian (double x, double y) const
	returns the local jacobian.
virtual void	transformErrors (Point const &where, const double *vIn, double *vOut) const
	transform errors (represented as double[3] in order V(xx),V(yy),Cov(xy))
void	getParams (double *params) const
	params should be at least Npar() long
void	offsetParams (Eigen::VectorXd const &delta)
virtual std::unique_ptr< AstrometryTransform >	roughInverse (const Frame &region) const
	Rough inverse.
double	getCoefficient (std::size_t powX, std::size_t powY, std::size_t whichCoord) const
	Get the coefficient of a given power in x and y, for either the x or y coordinate.
double &	getCoefficient (std::size_t powX, std::size_t powY, std::size_t whichCoord)
	Get the coefficient of a given power in x and y, for either the x or y coordinate.

Protected Member Functions
double &	a11 ()
double &	a12 ()
double &	a21 ()
double &	a22 ()
double &	dx ()
double &	dy ()

Detailed Description

just here to provide a specialized constructor, and fit.

Definition at line 497 of file AstrometryTransform.h.

Constructor & Destructor Documentation

AstrometryTransformLinearShift() [1/2]

lsst::jointcal::AstrometryTransformLinearShift::AstrometryTransformLinearShift ( double ox = 0., double oy = 0. )

inline

Add ox and oy.

Definition at line 501 of file AstrometryTransform.h.

            : AstrometryTransformLinear(ox, oy, 1., 0., 0., 1.) {}

AstrometryTransformLinearShift() [2/2]

lsst::jointcal::AstrometryTransformLinearShift::AstrometryTransformLinearShift ( Point const & point )

inline

Definition at line 503 of file AstrometryTransform.h.

            : AstrometryTransformLinear(point.x, point.y, 1., 0., 0., 1.){};

Member Function Documentation

__str__()

std::string lsst::jointcal::AstrometryTransform::__str__ ( ) const

inlineinherited

Definition at line 94 of file AstrometryTransform.h.

                              {
        std::stringstream s;
        print(s);
        return s.str();
    }

a11()

double & lsst::jointcal::AstrometryTransformLinear::a11 ( )

inlineprotectedinherited

Definition at line 479 of file AstrometryTransform.h.

{ return getCoefficient(1, 0, 0); }

A11()

double lsst::jointcal::AstrometryTransformLinear::A11 ( ) const

inlineinherited

Definition at line 471 of file AstrometryTransform.h.

{ return getCoefficient(1, 0, 0); }

a12()

double & lsst::jointcal::AstrometryTransformLinear::a12 ( )

inlineprotectedinherited

Definition at line 480 of file AstrometryTransform.h.

{ return getCoefficient(0, 1, 0); }

A12()

double lsst::jointcal::AstrometryTransformLinear::A12 ( ) const

inlineinherited

Definition at line 472 of file AstrometryTransform.h.

{ return getCoefficient(0, 1, 0); }

a21()

double & lsst::jointcal::AstrometryTransformLinear::a21 ( )

inlineprotectedinherited

Definition at line 481 of file AstrometryTransform.h.

{ return getCoefficient(1, 0, 1); }

A21()

double lsst::jointcal::AstrometryTransformLinear::A21 ( ) const

inlineinherited

Definition at line 473 of file AstrometryTransform.h.

{ return getCoefficient(1, 0, 1); }

a22()

double & lsst::jointcal::AstrometryTransformLinear::a22 ( )

inlineprotectedinherited

Definition at line 482 of file AstrometryTransform.h.

{ return getCoefficient(0, 1, 1); }

A22()

double lsst::jointcal::AstrometryTransformLinear::A22 ( ) const

inlineinherited

Definition at line 474 of file AstrometryTransform.h.

{ return getCoefficient(0, 1, 1); }

apply() [1/4]

virtual void lsst::jointcal::AstrometryTransform::apply ( double xIn, double yIn, double & xOut, double & yOut ) const

virtual

Reimplemented from lsst::jointcal::AstrometryTransformLinear.

apply() [2/4]

Frame lsst::jointcal::AstrometryTransform::apply	(	Frame const &	inputframe,
		bool	inscribed ) const

Transform a bounding box, taking either the inscribed or circumscribed box.

Parameters

[in]	inputframe	The frame to be transformed.
[in]	inscribed	Return the inscribed (true) or circumscribed (false) box.

Returns

The transformed frame.

Definition at line 89 of file AstrometryTransform.cc.

                                                                              {
    // 2 opposite corners
    double xtmin1, xtmax1, ytmin1, ytmax1;
    apply(inputframe.xMin, inputframe.yMin, xtmin1, ytmin1);
    apply(inputframe.xMax, inputframe.yMax, xtmax1, ytmax1);
    Frame fr1(std::min(xtmin1, xtmax1), std::min(ytmin1, ytmax1), std::max(xtmin1, xtmax1),
              std::max(ytmin1, ytmax1));
    // 2 other corners
    double xtmin2, xtmax2, ytmin2, ytmax2;
    apply(inputframe.xMin, inputframe.yMax, xtmin2, ytmax2);
    apply(inputframe.xMax, inputframe.yMin, xtmax2, ytmin2);
    Frame fr2(std::min(xtmin2, xtmax2), std::min(ytmin2, ytmax2), std::max(xtmin2, xtmax2),
              std::max(ytmin2, ytmax2));
 
    if (inscribed) return fr1 * fr2;
    return fr1 + fr2;
}

apply() [3/4]

Point lsst::jointcal::AstrometryTransform::apply ( Point const & in ) const

inline

All these apply(..) shadow the virtual one in derived classes, unless one writes "using AstrometryTransform::apply".

Definition at line 75 of file AstrometryTransform.h.

                                       {
        double xout, yout;
        apply(in.x, in.y, xout, yout);
        return Point(xout, yout);
    }

apply() [4/4]

void lsst::jointcal::AstrometryTransform::apply ( Point const & in, Point & out ) const

inline

applies the tranfo to in and writes into out. Is indeed virtual.

Definition at line 71 of file AstrometryTransform.h.

{ apply(in.x, in.y, out.x, out.y); }

clone()

std::unique_ptr< AstrometryTransform > lsst::jointcal::AstrometryTransformLinear::clone ( ) const

inlineoverridevirtualinherited

returns a copy (allocated by new) of the transformation.

Implements lsst::jointcal::AstrometryTransform.

Definition at line 464 of file AstrometryTransform.h.

                                                              {
        return std::unique_ptr<AstrometryTransform>(new AstrometryTransformLinear(*this));
    }

coeffOrZero()

double lsst::jointcal::AstrometryTransformPolynomial::coeffOrZero ( std::size_t powX, std::size_t powY, std::size_t whichCoord ) const

inherited

read access, zero if beyond order

Definition at line 756 of file AstrometryTransform.cc.

                                                                              {
    //  assert((degX+degY<=order) && whichCoord<2);
    assert(whichCoord < 2);
    if (degX + degY <= _order)
        return _coeffs[(degX + degY) * (degX + degY + 1) / 2 + degY + whichCoord * _nterms];
    return 0;
}

composeAndReduce() [1/2]

std::unique_ptr< AstrometryTransform > lsst::jointcal::AstrometryTransform::composeAndReduce ( AstrometryTransform const & right ) const

virtualinherited

Return a reduced composition of newTransform = this(right()), or nullptr if it cannot be reduced.

"Reduced" in this context means that they are capable of being merged into a single transform, for example, for two polynomials:

\[ f(x) = 1 + x^2, g(x) = -1 + 3x \]

we would have h = f.composeAndReduce(g) == 2 - 6x + 9x^2.

To be overloaded by derived classes if they can properly reduce the composition.

Parameters

right

The transform to apply first.

Returns

The new reduced and composed AstrometryTransform, or nullptr if no such reduction is possible.

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 131 of file AstrometryTransform.cc.

                                           {  // by default no way to compose
    return std::unique_ptr<AstrometryTransform>(nullptr);
}

composeAndReduce() [2/2]

std::unique_ptr< AstrometryTransform > lsst::jointcal::AstrometryTransformPolynomial::composeAndReduce ( AstrometryTransformPolynomial const & right ) const

inherited

Return a reduced composition of newTransform = this(right()), or nullptr if it cannot be reduced.

"Reduced" in this context means that they are capable of being merged into a single transform, for example, for two polynomials:

\[ f(x) = 1 + x^2, g(x) = -1 + 3x \]

we would have h = f.composeAndReduce(g) == 2 - 6x + 9x^2.

To be overloaded by derived classes if they can properly reduce the composition.

Parameters

right

The transform to apply first.

Returns

The new reduced and composed AstrometryTransform, or nullptr if no such reduction is possible.

Definition at line 944 of file AstrometryTransform.cc.

                                                          {
    if (getOrder() == 1 && right.getOrder() == 1)
        return std::make_unique<AstrometryTransformLinear>((*this) * (right));  // does the composition
    else
        return std::make_unique<AstrometryTransformPolynomial>((*this) * (right));  // does the composition
}

computeDerivative()

void lsst::jointcal::AstrometryTransformLinear::computeDerivative ( Point const & where, AstrometryTransformLinear & derivative, double step = 0.01 ) const

overridevirtualinherited

Computes the local Derivative of a transform, w.r.t.

the Derivative is represented by a AstrometryTransformLinear, in which (hopefully), the offset terms are zero.

position.

Step is used for numerical derivation.

Derivative should transform a vector of offsets into a vector of offsets.

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 1251 of file AstrometryTransform.cc.

                                                                      {
    derivative = *this;
    derivative.getCoefficient(0, 0, 0) = 0;
    derivative.getCoefficient(0, 0, 1) = 0;
}

determinant()

double lsst::jointcal::AstrometryTransformPolynomial::determinant ( ) const

inherited

Definition at line 826 of file AstrometryTransform.cc.

                                                        {
    if (_order >= 1)
        return getCoefficient(1, 0, 0) * getCoefficient(0, 1, 1) -
               getCoefficient(0, 1, 0) * getCoefficient(1, 0, 1);
    return 0;
}

dx()

double & lsst::jointcal::AstrometryTransformLinear::dx ( )

inlineprotectedinherited

Definition at line 483 of file AstrometryTransform.h.

{ return getCoefficient(0, 0, 0); }

Dx()

double lsst::jointcal::AstrometryTransformLinear::Dx ( ) const

inlineinherited

Definition at line 475 of file AstrometryTransform.h.

{ return getCoefficient(0, 0, 0); }

dy()

double & lsst::jointcal::AstrometryTransformLinear::dy ( )

inlineprotectedinherited

Definition at line 484 of file AstrometryTransform.h.

{ return getCoefficient(0, 0, 1); }

Dy()

double lsst::jointcal::AstrometryTransformLinear::Dy ( ) const

inlineinherited

Definition at line 476 of file AstrometryTransform.h.

{ return getCoefficient(0, 0, 1); }

fit()

double lsst::jointcal::AstrometryTransformLinearShift::fit ( StarMatchList const & starMatchList )

virtual

fits a transform to a std::list of Point pairs (p1,p2, the Point fields in StarMatch).

After the fit this(p1) yields approximately p2. The returned value is the sum of squared residuals. If you want to fit a partial transform (e.g. such that this(T1(p1)) = T2(p2), use StarMatchList::applyTransform beforehand.

Implements lsst::jointcal::AstrometryTransform.

Definition at line 1309 of file AstrometryTransform.cc.

                                                                             {
    std::size_t npairs = starMatchList.size();
    if (npairs < 3) {
        LOGLS_FATAL(_log, "AstrometryTransformLinearShift::fit trying to fit a linear transform with only "
                                  << npairs << " matches.");
        return -1;
    }
 
    double sumr2 = 0; /* used to compute chi2 without relooping */
    /* loop on pairs  and fill */
    Eigen::VectorXd B(2);
    B.setZero();
    Eigen::MatrixXd A(2, 2);
    A.setZero();
 
    for (auto const &it : starMatchList) {
        FatPoint const &point1 = it.point1;
        FatPoint const &point2 = it.point2;
        double deltax = point2.x - point1.x;
        double deltay = point2.y - point1.y;
        double vxx = point1.vx + point2.vx;
        double vyy = point1.vy + point2.vy;
        double vxy = point1.vxy + point2.vxy;
        double det = vxx * vyy - vxy * vxy;
        double wxx = vyy / det;
        double wyy = vxx / det;
        double wxy = -vxy / det;
        B(0) += deltax * wxx + wxy * deltay;
        B(1) += deltay * wyy + wxy * deltax;
        A(0, 0) += wxx;
        A(1, 1) += wyy;
        A(0, 1) += wxy;
        sumr2 += deltax * deltax * wxx + deltay * deltay * wyy + 2. * wxy * deltax * deltay;
    }
    double det = A(0, 0) * A(1, 1) - A(0, 1) * A(1, 0);
    if (det <= 0) return -1;
    double tmp = A(0, 0);
    A(0, 0) = A(1, 1) / det;
    A(1, 1) = tmp / det;
    A(0, 1) = A(1, 0) = -A(0, 1) / det;
    Eigen::VectorXd sol = A * B;
    (*this) = AstrometryTransformLinearShift(sol(0), sol(1));
    return (sumr2 - sol.dot(B));  // chi2 compact form
}

getCoefficient() [1/2]

double & lsst::jointcal::AstrometryTransformPolynomial::getCoefficient ( std::size_t powX, std::size_t powY, std::size_t whichCoord )

inherited

Get the coefficient of a given power in x and y, for either the x or y coordinate.

Definition at line 750 of file AstrometryTransform.cc.

                                                                            {
    assert((degX + degY <= _order) && whichCoord < 2);
    return _coeffs[(degX + degY) * (degX + degY + 1) / 2 + degY + whichCoord * _nterms];
}

getCoefficient() [2/2]

double lsst::jointcal::AstrometryTransformPolynomial::getCoefficient ( std::size_t powX, std::size_t powY, std::size_t whichCoord ) const

inherited

Get the coefficient of a given power in x and y, for either the x or y coordinate.

Definition at line 741 of file AstrometryTransform.cc.

                                                                                 {
    assert((degX + degY <= _order) && whichCoord < 2);
    /* this assertion above is enough to ensure that the index used just
       below is within bounds since the reserved length is
       2*_nterms=(order+1)*(order+2) */
    return _coeffs[(degX + degY) * (degX + degY + 1) / 2 + degY + whichCoord * _nterms];
}

getJacobian() [1/2]

double lsst::jointcal::AstrometryTransform::getJacobian ( double x, double y ) const

virtualinherited

returns the local jacobian.

Definition at line 100 of file AstrometryTransform.cc.

                                                                            {
    double x2, y2;
    double eps = x * 0.01;
    if (eps == 0) eps = 0.01;
    apply(x, y, x2, y2);
    double dxdx, dydx;
    apply(x + eps, y, dxdx, dydx);
    dxdx -= x2;
    dydx -= y2;
    double dxdy, dydy;
    apply(x, y + eps, dxdy, dydy);
    dxdy -= x2;
    dydy -= y2;
    return ((dxdx * dydy - dxdy * dydx) / (eps * eps));
}

getJacobian() [2/2]

virtual double lsst::jointcal::AstrometryTransform::getJacobian ( Point const & point ) const

inlinevirtualinherited

returns the local jacobian.

Definition at line 110 of file AstrometryTransform.h.

{ return getJacobian(point.x, point.y); }

getNpar()

std::size_t lsst::jointcal::AstrometryTransformLinearShift::getNpar ( ) const

inlinevirtual

returns the number of parameters (to compute chi2's)

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 507 of file AstrometryTransform.h.

{ return 2; }

getOrder()

std::size_t lsst::jointcal::AstrometryTransformPolynomial::getOrder ( ) const

inlineinherited

Returns the polynomial order.

Definition at line 307 of file AstrometryTransform.h.

{ return _order; }

getParams()

void lsst::jointcal::AstrometryTransform::getParams ( double * params ) const

inherited

params should be at least Npar() long

Definition at line 217 of file AstrometryTransform.cc.

                                                        {
    std::size_t npar = getNpar();
    for (std::size_t i = 0; i < npar; ++i) params[i] = paramRef(i);
}

inverseTransform()

std::unique_ptr< AstrometryTransform > lsst::jointcal::AstrometryTransformLinear::inverseTransform ( double precision, const Frame & region ) const

overridevirtualinherited

returns an inverse transform. Numerical if not overloaded.

precision and region refer to the "input" side of this, and hence to the output side of the returned AstrometryTransform.

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 1289 of file AstrometryTransform.cc.

                                                                                                      {
    return std::unique_ptr<AstrometryTransform>(new AstrometryTransformLinear(inverted()));
}

inverted()

AstrometryTransformLinear lsst::jointcal::AstrometryTransformLinear::inverted ( ) const

inherited

returns the inverse: T1 = T2.inverted();

Definition at line 1262 of file AstrometryTransform.cc.

                                                                    {
    //
    //   (T1,M1) * (T2,M2) = 1 i.e (0,1) implies
    //   T1 = -M1 * T2
    //   M1 = M2^(-1)
    //
 
    double a11 = A11();
    double a12 = A12();
    double a21 = A21();
    double a22 = A22();
    double d = (a11 * a22 - a12 * a21);
    if (d == 0) {
        LOGL_FATAL(_log,
                   "AstrometryTransformLinear::invert singular transformation: transform contents will be "
                   "dumped to stderr.");
        print(cerr);
    }
 
    AstrometryTransformLinear result(0, 0, a22 / d, -a12 / d, -a21 / d, a11 / d);
    double rdx, rdy;
    result.apply(Dx(), Dy(), rdx, rdy);
    result.dx() = -rdx;
    result.dy() = -rdy;
    return result;
}

linearApproximation()

AstrometryTransformLinear lsst::jointcal::AstrometryTransformLinear::linearApproximation ( Point const & where, double step = 0.01 ) const

overridevirtualinherited

linear (local) approximation.

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 1258 of file AstrometryTransform.cc.

                                                                                                          {
    return *this;
}

offsetParams()

void lsst::jointcal::AstrometryTransform::offsetParams ( Eigen::VectorXd const & delta )

inherited

Definition at line 222 of file AstrometryTransform.cc.

                                                                 {
    std::size_t npar = getNpar();
    for (std::size_t i = 0; i < npar; ++i) paramRef(i) += delta[i];
}

operator*() [1/2]

AstrometryTransformLinear lsst::jointcal::AstrometryTransformLinear::operator* ( AstrometryTransformLinear const & right ) const

inherited

enables to combine linear tranformations: T1=T2*T3 is legal.

Definition at line 1236 of file AstrometryTransform.cc.

                                                                                                           {
    // There is a general routine in AstrometryTransformPolynomial that would do the job:
    //  return AstrometryTransformLinear(AstrometryTransformPolynomial::operator*(right));
    // however, we are using this composition of linear stuff heavily in
    // AstrometryTransform::linearApproximation, itself used in inverseTransform::apply.
    // So, for sake of efficiency, and since it is easy, we take a shortcut:
    AstrometryTransformLinear result;
    apply(right.Dx(), right.Dy(), result.dx(), result.dy());
    result.a11() = A11() * right.A11() + A12() * right.A21();
    result.a12() = A11() * right.A12() + A12() * right.A22();
    result.a21() = A21() * right.A11() + A22() * right.A21();
    result.a22() = A21() * right.A12() + A22() * right.A22();
    return result;
}

operator*() [2/2]

AstrometryTransformPolynomial lsst::jointcal::AstrometryTransformPolynomial::operator* ( AstrometryTransformPolynomial const & right ) const

inherited

Composition (internal stuff in quadruple precision)

Definition at line 1052 of file AstrometryTransform.cc.

                                                          {
    // split each transform into 2d polynomials
    PolyXY plx(*this, 0);
    PolyXY ply(*this, 1);
    PolyXY prx(right, 0);
    PolyXY pry(right, 1);
 
    // compute the compositions
    PolyXY rx(composition(plx, prx, pry));
    PolyXY ry(composition(ply, prx, pry));
 
    // copy the results the hard way.
    AstrometryTransformPolynomial result(_order * right._order);
    for (std::size_t px = 0; px <= result._order; ++px)
        for (std::size_t py = 0; py <= result._order - px; ++py) {
            result.getCoefficient(px, py, 0) = rx.getCoefficient(px, py);
            result.getCoefficient(px, py, 1) = ry.getCoefficient(px, py);
        }
    return result;
}

operator+()

AstrometryTransformPolynomial lsst::jointcal::AstrometryTransformPolynomial::operator+ ( AstrometryTransformPolynomial const & right ) const

inherited

Addition.

Definition at line 1074 of file AstrometryTransform.cc.

                                                          {
    if (_order >= right._order) {
        AstrometryTransformPolynomial res(*this);
        for (std::size_t i = 0; i <= right._order; ++i)
            for (std::size_t j = 0; j <= right._order - i; ++j) {
                res.getCoefficient(i, j, 0) += right.getCoefficient(i, j, 0);
                res.getCoefficient(i, j, 1) += right.getCoefficient(i, j, 1);
            }
        return res;
    } else
        return (right + (*this));
}

operator-()

AstrometryTransformPolynomial lsst::jointcal::AstrometryTransformPolynomial::operator- ( AstrometryTransformPolynomial const & right ) const

inherited

Subtraction.

Definition at line 1088 of file AstrometryTransform.cc.

                                                          {
    AstrometryTransformPolynomial res(std::max(_order, right._order));
    for (std::size_t i = 0; i <= res._order; ++i)
        for (std::size_t j = 0; j <= res._order - i; ++j) {
            res.getCoefficient(i, j, 0) = coeffOrZero(i, j, 0) - right.coeffOrZero(i, j, 0);
            res.getCoefficient(i, j, 1) = coeffOrZero(i, j, 1) - right.coeffOrZero(i, j, 1);
        }
    return res;
}

paramDerivatives()

void lsst::jointcal::AstrometryTransformPolynomial::paramDerivatives ( Point const & where, double * dx, double * dy ) const

overridevirtualinherited

Derivative w.r.t parameters.

Derivatives should be al least 2*NPar long. first Npar, for x, last Npar for y.

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 776 of file AstrometryTransform.cc.

              { /* first half : dxout/dpar, second half : dyout/dpar */
    computeMonomials(where.x, where.y, dx);
    for (std::size_t k = 0; k < _nterms; ++k) {
        dy[_nterms + k] = dx[k];
        dx[_nterms + k] = dy[k] = 0;
    }
}

paramRef() [1/2]

double lsst::jointcal::AstrometryTransformPolynomial::paramRef ( Eigen::Index i ) const

overridevirtualinherited

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 766 of file AstrometryTransform.cc.

                                                                       {
    assert(i < 2 * Eigen::Index(_nterms));
    return _coeffs[i];
}

paramRef() [2/2]

double & lsst::jointcal::AstrometryTransformPolynomial::paramRef ( Eigen::Index i )

overridevirtualinherited

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 771 of file AstrometryTransform.cc.

                                                                  {
    assert(i < 2 * Eigen::Index(_nterms));
    return _coeffs[i];
}

print()

void lsst::jointcal::AstrometryTransformLinear::print ( std::ostream & out ) const

overridevirtualinherited

prints the transform coefficients to stream.

Implements lsst::jointcal::AstrometryTransform.

Definition at line 1294 of file AstrometryTransform.cc.

                                                           {
    auto oldPrecision = stream.precision();
    stream.precision(12);
    stream << "Linear AstrometryTransform:" << std::endl;
    stream << A11() << " " << A12() << " + " << Dx() << std::endl;
    stream << A21() << " " << A22() << " + " << Dy() << std::endl;
    stream.precision(oldPrecision);
    stream << "determinant = " << determinant();
    stream.precision(oldPrecision);
}

read()

void lsst::jointcal::AstrometryTransformPolynomial::read ( std::istream & s )

inherited

Definition at line 1114 of file AstrometryTransform.cc.

                                                   {
    int format;
    s >> format;
    if (format != 1)
        throw LSST_EXCEPT(pex::exceptions::InvalidParameterError,
                          " AstrometryTransformPolynomial::read : format is not 1 ");
 
    string order;
    s >> order >> _order;
    if (order != "order")
        throw LSST_EXCEPT(pex::exceptions::InvalidParameterError,
                          " AstrometryTransformPolynomial::read : expecting \"order\" and found " + order);
    setOrder(_order);
    for (std::size_t k = 0; k < 2 * _nterms; ++k) s >> _coeffs[k];
}

roughInverse()

std::unique_ptr< AstrometryTransform > lsst::jointcal::AstrometryTransform::roughInverse ( const Frame & region ) const

virtualinherited

Rough inverse.

Stored by the numerical inverter to guess starting point for the trials. Just here to enable overloading.

Reimplemented in lsst::jointcal::AstrometryTransformInverse, lsst::jointcal::TanPixelToRaDec, and lsst::jointcal::TanRaDecToPixel.

Definition at line 196 of file AstrometryTransform.cc.

                                                                                              {
    // "in" and "out" refer to the inverse direction.
    Point centerOut = region.getCenter();
    Point centerIn = apply(centerOut);
    AstrometryTransformLinear der;
    computeDerivative(centerOut, der, std::sqrt(region.getArea()) / 5.);
    der = der.inverted();
    der = AstrometryTransformLinearShift(centerOut.x, centerOut.y) * der *
          AstrometryTransformLinearShift(-centerIn.x, -centerIn.y);
    return std::unique_ptr<AstrometryTransform>(new AstrometryTransformLinear(der));
}

toAstMap()

std::shared_ptr< ast::Mapping > lsst::jointcal::AstrometryTransformPolynomial::toAstMap ( jointcal::Frame const & domain ) const

overridevirtualinherited

Create an equivalent AST mapping for this transformation, including an analytic inverse if possible.

Parameters

domain

The domain of the transform, to help find an inverse.

Returns

An AST Mapping that represents this transformation.

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 1099 of file AstrometryTransform.cc.

                                                                                                   {
    auto inverse = inversePolyTransform(*this, domain, 1e-7, _order + 2, 100);
    return std::make_shared<ast::PolyMap>(toAstPolyMapCoefficients(), inverse->toAstPolyMapCoefficients());
}

transformErrors()

void lsst::jointcal::AstrometryTransform::transformErrors ( Point const & where, const double * vIn, double * vOut ) const

virtualinherited

transform errors (represented as double[3] in order V(xx),V(yy),Cov(xy))

Definition at line 163 of file AstrometryTransform.cc.

                                                                                                   {
    AstrometryTransformLinear der;
    computeDerivative(where, der, 0.01);
    double a11 = der.A11();
    double a22 = der.A22();
    double a21 = der.A21();
    double a12 = der.A12();
 
    /*      (a11 a12)          (vxx  vxy)
       M =  (       )  and V = (        )
            (a21 a22)          (xvy  vyy)
 
       Vxx = Vin[0], vyy = Vin[1], Vxy = Vin[2];
       we want to compute M*V*tp(M)
       A lin alg light package would be perfect...
    */
    int xx = 0;
    int yy = 1;
    int xy = 2;
    // M*V :
 
    double b11 = a11 * vIn[xx] + a12 * vIn[xy];
    double b22 = a21 * vIn[xy] + a22 * vIn[yy];
    double b12 = a11 * vIn[xy] + a12 * vIn[yy];
    double b21 = a21 * vIn[xx] + a22 * vIn[xy];
 
    // (M*V) * tp(M)
 
    vOut[xx] = b11 * a11 + b12 * a12;
    vOut[xy] = b11 * a21 + b12 * a22;
    vOut[yy] = b21 * a21 + b22 * a22;
}

transformPosAndErrors()

void lsst::jointcal::AstrometryTransformPolynomial::transformPosAndErrors ( const FatPoint & in, FatPoint & out ) const

overridevirtualinherited

a mix of apply and Derivative

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 657 of file AstrometryTransform.cc.

                                                                                                 {
    /*
       The results from this routine were compared to what comes out
       from apply and transformErrors. The Derivative routine was
       checked against numerical derivatives from
       AstrometryTransform::Derivative. (P.A dec 2009).
 
       This routine could be made much simpler by calling apply and
       Derivative (i.e. you just suppress it, and the fallback is the
       generic version in AstrometryTransform).  BTW, I checked that both routines
       provide the same result. This version is however faster
       (monomials get recycled).
    */
    double monomials[_nterms];  // VLA
 
    FatPoint res;  // to store the result, because nothing forbids &in == &out.
 
    double dermx[2 * _nterms];        // monomials for derivative w.r.t. x (VLA)
    double *dermy = dermx + _nterms;  // same for y
    double xin = in.x;
    double yin = in.y;
 
    double xx = 1;
    double xxm1 = 1;  // xx^(ix-1)
    for (std::size_t ix = 0; ix <= _order; ++ix) {
        std::size_t k = (ix) * (ix + 1) / 2;
        // iy = 0
        dermx[k] = ix * xxm1;
        dermy[k] = 0;
        monomials[k] = xx;
        k += ix + 2;
        double yy = yin;
        double yym1 = 1;  // yy^(iy-1)
        for (std::size_t iy = 1; iy <= _order - ix; ++iy) {
            monomials[k] = xx * yy;
            dermx[k] = ix * xxm1 * yy;
            dermy[k] = iy * xx * yym1;
            yym1 *= yin;
            yy *= yin;
            k += ix + iy + 2;
        }
        xx *= xin;
        if (ix >= 1) xxm1 *= xin;
    }
 
    // output position
    double xout = 0, yout = 0;
    const double *c = &_coeffs[0];
    const double *pm = &monomials[0];
    for (int k = _nterms; k--;) xout += (*(pm++)) * (*(c++));
    pm = &monomials[0];
    for (int k = _nterms; k--;) yout += (*(pm++)) * (*(c++));
    res.x = xout;
    res.y = yout;
 
    // derivatives
    c = &_coeffs[0];
    const double *mx = &dermx[0];
    const double *my = &dermy[0];
    double a11 = 0, a12 = 0;
    for (int k = _nterms; k--;) {
        a11 += (*(mx++)) * (*c);
        a12 += (*(my++)) * (*(c++));
    }
 
    double a21 = 0, a22 = 0;
    mx = &dermx[0];
    my = &dermy[0];
    for (int k = _nterms; k--;) {
        a21 += (*(mx++)) * (*c);
        a22 += (*(my++)) * (*(c++));
    }
 
    // output co-variance
    res.vx = a11 * (a11 * in.vx + 2 * a12 * in.vxy) + a12 * a12 * in.vy;
    res.vy = a21 * a21 * in.vx + a22 * a22 * in.vy + 2. * a21 * a22 * in.vxy;
    res.vxy = a21 * a11 * in.vx + a22 * a12 * in.vy + (a21 * a12 + a11 * a22) * in.vxy;
    out = res;
}

transformStar()

void lsst::jointcal::AstrometryTransform::transformStar ( FatPoint & in ) const

inlineinherited

Definition at line 107 of file AstrometryTransform.h.

{ transformPosAndErrors(in, in); }

write() [1/2]

void lsst::jointcal::AstrometryTransform::write ( const std::string & fileName ) const

inherited

Definition at line 247 of file AstrometryTransform.cc.

                                                               {
    ofstream s(fileName.c_str());
    write(s);
    bool ok = !s.fail();
    s.close();
    if (!ok)
        throw LSST_EXCEPT(pex::exceptions::InvalidParameterError,
                          "AstrometryTransform::write, something went wrong for file " + fileName);
}

write() [2/2]

void lsst::jointcal::AstrometryTransformPolynomial::write ( std::ostream & s ) const

overridevirtualinherited

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 1104 of file AstrometryTransform.cc.

                                                          {
    s << " AstrometryTransformPolynomial 1" << endl;
    s << "order " << _order << endl;
    int oldprec = s.precision();
    s << setprecision(12);
    for (std::size_t k = 0; k < 2 * _nterms; ++k) s << _coeffs[k] << ' ';
    s << endl;
    s << setprecision(oldprec);
}

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/jointcal/gbb8dafda3b+e9bba80f27/include/lsst/jointcal/AstrometryTransform.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/jointcal/gbb8dafda3b+e9bba80f27/src/AstrometryTransform.cc