lsst::jointcal::AstrometryTransformLinear Class Reference

implements the linear transformations (6 real coefficients). More...

#include <AstrometryTransform.h>

Inheritance diagram for lsst::jointcal::AstrometryTransformLinear:

Public Member Functions
	AstrometryTransformLinear ()
	the default constructor constructs the do-nothing transformation. More...
	AstrometryTransformLinear (AstrometryTransformPolynomial const &transform)
	This triggers an exception if P.getOrder() != 1. More...
AstrometryTransformLinear	operator* (AstrometryTransformLinear const &right) const
	enables to combine linear tranformations: T1=T2*T3 is legal. More...
AstrometryTransformLinear	inverted () const
	returns the inverse: T1 = T2.inverted(); More...
void	computeDerivative (Point const &where, AstrometryTransformLinear &derivative, const double step=0.01) const
	specialised analytic routine More...
AstrometryTransformLinear	linearApproximation (Point const &where, const double step=0.01) const
	linear (local) approximation. More...
	AstrometryTransformLinear (const double ox, const double oy, const double aa11, const double aa12, const double aa21, const double aa22)
	Construct a AstrometryTransformLinear from parameters. More...
	AstrometryTransformLinear (AstrometryTransformIdentity const &)
	Handy converter: More...
std::unique_ptr< AstrometryTransform >	clone () const
	returns a copy (allocated by new) of the transformation. More...
std::unique_ptr< AstrometryTransform >	inverseTransform (const double precision, const Frame &region) const
	returns an inverse transform. Numerical if not overloaded. More...
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. More...
void	apply (const double xIn, const double yIn, double &xOut, double &yOut) const override
void	apply (Point const &in, Point &out) const
	applies the tranfo to in and writes into out. Is indeed virtual. More...
Point	apply (Point const &in) const
	All these apply(..) shadow the virtual one in derived classes, unless one writes "using AstrometryTransform::apply". More...
Frame	apply (Frame const &inputframe, bool inscribed) const
	Transform a bounding box, taking either the inscribed or circumscribed box. More...
virtual void	transformPosAndErrors (const FatPoint &in, FatPoint &out) const override
	a mix of apply and Derivative More...
std::size_t	getNpar () const override
	total number of parameters More...
void	dump (std::ostream &stream=std::cout) const override
	print out of coefficients in a readable form. More...
double	fit (StarMatchList const &starMatchList) override
	guess what More...
AstrometryTransformPolynomial	operator* (AstrometryTransformPolynomial const &right) const
	Composition (internal stuff in quadruple precision) More...
AstrometryTransformPolynomial	operator+ (AstrometryTransformPolynomial const &right) const
	Addition. More...
AstrometryTransformPolynomial	operator- (AstrometryTransformPolynomial const &right) const
	Subtraction. More...
std::unique_ptr< AstrometryTransform >	composeAndReduce (AstrometryTransformPolynomial const &right) const
	Return a reduced composition of newTransform = this(right()), or nullptr if it cannot be reduced. More...
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. More...
double	coeff (std::size_t powX, std::size_t powY, std::size_t whichCoord) const
	access to coefficients (read only) More...
double &	coeff (std::size_t powX, std::size_t powY, std::size_t whichCoord)
	write access More...
double	coeffOrZero (std::size_t powX, std::size_t powY, std::size_t whichCoord) const
	read access, zero if beyond order More...
double	determinant () const
double	paramRef (Eigen::Index const i) const override
double &	paramRef (Eigen::Index const i) override
void	paramDerivatives (Point const &where, double *dx, double *dy) const override
	Derivative w.r.t parameters. More...
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. More...
void	write (std::ostream &s) const override
void	write (const std::string &fileName) const
void	read (std::istream &s)
std::string	__str__ ()
void	transformStar (FatPoint &in) const
virtual double	getJacobian (Point const &point) const
	returns the local jacobian. More...
virtual double	getJacobian (const double x, const double y) const
	returns the local jacobian. More...
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)) More...
void	getParams (double *params) const
	params should be at least Npar() long More...
void	offsetParams (Eigen::VectorXd const &delta)
virtual std::unique_ptr< AstrometryTransform >	roughInverse (const Frame &region) const
	Rough inverse. More...

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

Friends
class	AstrometryTransform
class	AstrometryTransformIdentity
class	AstrometryTransformPolynomial

Detailed Description

implements the linear transformations (6 real coefficients).

Definition at line 426 of file AstrometryTransform.h.

Constructor & Destructor Documentation

AstrometryTransformLinear() [1/4]

lsst::jointcal::AstrometryTransformLinear::AstrometryTransformLinear ( )

inline

the default constructor constructs the do-nothing transformation.

Definition at line 431 of file AstrometryTransform.h.

: AstrometryTransformPolynomial(1){};

AstrometryTransformLinear() [2/4]

lsst::jointcal::AstrometryTransformLinear::AstrometryTransformLinear ( AstrometryTransformPolynomial const &  transform )

explicit

This triggers an exception if P.getOrder() != 1.

Definition at line 1211 of file AstrometryTransform.cc.

        : AstrometryTransformPolynomial(1) {
    if (transform.getOrder() != 1)
        throw pexExcept::InvalidParameterError(
                "Trying to build a AstrometryTransformLinear from a higher order transform. Aborting. ");
    (AstrometryTransformPolynomial &)(*this) = transform;
}

AstrometryTransformLinear() [3/4]

lsst::jointcal::AstrometryTransformLinear::AstrometryTransformLinear	(	const double	ox,
		const double	oy,
		const double	aa11,
		const double	aa12,
		const double	aa21,
		const double	aa22
	)

Construct a AstrometryTransformLinear from parameters.

Definition at line 1200 of file AstrometryTransform.cc.

        : AstrometryTransformPolynomial(1) {
    dx() = Dx;
    a11() = A11;
    a12() = A12;
    dy() = Dy;
    a21() = A21;
    a22() = A22;
}

AstrometryTransformLinear() [4/4]

lsst::jointcal::AstrometryTransformLinear::AstrometryTransformLinear ( AstrometryTransformIdentity const &  )

inline

Handy converter:

Definition at line 459 of file AstrometryTransform.h.

: AstrometryTransformPolynomial(1){};

Member Function Documentation

__str__()

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

inlineinherited

Definition at line 94 of file AstrometryTransform.h.

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

A11()

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

inline

Definition at line 467 of file AstrometryTransform.h.

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

a11()

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

inlineprotected

Definition at line 475 of file AstrometryTransform.h.

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

A12()

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

inline

Definition at line 468 of file AstrometryTransform.h.

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

a12()

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

inlineprotected

Definition at line 476 of file AstrometryTransform.h.

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

A21()

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

inline

Definition at line 469 of file AstrometryTransform.h.

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

a21()

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

inlineprotected

Definition at line 477 of file AstrometryTransform.h.

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

A22()

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

inline

Definition at line 470 of file AstrometryTransform.h.

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

a22()

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

inlineprotected

Definition at line 478 of file AstrometryTransform.h.

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

apply() [1/4]

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

inlineinherited

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); }

apply() [2/4]

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

inlineinherited

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() [3/4]

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

inherited

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 75 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() [4/4]

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

overridevirtualinherited

Implements lsst::jointcal::AstrometryTransform.

Definition at line 570 of file AstrometryTransform.cc.

                                                              {
    /*
      This routine computes the monomials only once for both
      polynomials.  This is why AstrometryTransformPolynomial does not use an auxilary
      class (such as PolyXY) to handle each polynomial.

      The code works even if &xIn == &xOut (or &yIn == &yOut)
      It uses Variable Length Allocation (VLA) rather than a vector<double>
      because allocating the later costs about 50 ns. All VLA uses are tagged.
    */
    double monomials[_nterms];  // this is VLA, which is (perhaps) not casher C++
    computeMonomials(xIn, yIn, monomials);

    xOut = 0;
    yOut = 0;
    const double *c = &_coeffs[0];
    const double *pm = &monomials[0];
    // the ordering of the coefficients and the monomials are identical.
    for (int k = _nterms; k--;) xOut += (*(pm++)) * (*(c++));
    pm = &monomials[0];
    for (int k = _nterms; k--;) yOut += (*(pm++)) * (*(c++));
}

clone()

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

inlinevirtual

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

Reimplemented from lsst::jointcal::AstrometryTransformPolynomial.

Definition at line 461 of file AstrometryTransform.h.

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

coeff() [1/2]

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

inherited

access to coefficients (read only)

Definition at line 738 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];
}

coeff() [2/2]

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

inherited

write access

Definition at line 747 of file AstrometryTransform.cc.

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

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 753 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 in lsst::jointcal::AstrometryTransformIdentity.

Definition at line 93 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 930 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, const double  step = 0.01  ) const

virtual

specialised analytic routine

Reimplemented from lsst::jointcal::AstrometryTransformPolynomial.

Definition at line 1234 of file AstrometryTransform.cc.

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

determinant()

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

inherited

Definition at line 812 of file AstrometryTransform.cc.

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

dump()

void lsst::jointcal::AstrometryTransformPolynomial::dump ( std::ostream &  stream = std::cout ) const

overridevirtualinherited

print out of coefficients in a readable form.

Implements lsst::jointcal::AstrometryTransform.

Definition at line 793 of file AstrometryTransform.cc.

                                                              {
    auto oldPrecision = stream.precision();
    stream.precision(12);
    for (std::size_t ic = 0; ic < 2; ++ic) {
        if (ic == 0)
            stream << "newx = ";
        else
            stream << "newy = ";
        for (std::size_t p = 0; p <= _order; ++p)
            for (std::size_t py = 0; py <= p; ++py) {
                if (p + py != 0) stream << " + ";
                stream << coeff(p - py, py, ic) << monomialString(p - py, py);
            }
        stream << endl;
    }
    if (_order > 0) stream << " Linear determinant = " << determinant() << endl;
    stream.precision(oldPrecision);
}

Dx()

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

inline

Definition at line 471 of file AstrometryTransform.h.

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

dx()

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

inlineprotected

Definition at line 479 of file AstrometryTransform.h.

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

Dy()

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

inline

Definition at line 472 of file AstrometryTransform.h.

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

dy()

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

inlineprotected

Definition at line 480 of file AstrometryTransform.h.

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

fit()

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

overridevirtualinherited

guess what

Implements lsst::jointcal::AstrometryTransform.

Reimplemented in lsst::jointcal::AstrometryTransformLinearRot, and lsst::jointcal::AstrometryTransformLinearShift.

Definition at line 912 of file AstrometryTransform.cc.

                                                                            {
    if (starMatchList.size() < _nterms) {
        LOGLS_FATAL(_log, "AstrometryTransformPolynomial::fit trying to fit a polynomial transform of order "
                                  << _order << " with only " << starMatchList.size() << " matches.");
        return -1;
    }

    AstrometryTransformPolynomial conditionner = shiftAndNormalize(starMatchList);

    computeFit(starMatchList, conditionner, false);               // get a rough solution
    computeFit(starMatchList, conditionner, true);                // weight with it
    double chi2 = computeFit(starMatchList, conditionner, true);  // once more

    (*this) = (*this) * conditionner;
    if (starMatchList.size() == _nterms) return 0;
    return chi2;
}

getJacobian() [1/2]

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); }

getJacobian() [2/2]

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

virtualinherited

returns the local jacobian.

Definition at line 98 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));
}

getNpar()

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

inlineoverridevirtualinherited

total number of parameters

Reimplemented from lsst::jointcal::AstrometryTransform.

Reimplemented in lsst::jointcal::AstrometryTransformLinearScale, lsst::jointcal::AstrometryTransformLinearRot, and lsst::jointcal::AstrometryTransformLinearShift.

Definition at line 323 of file AstrometryTransform.h.

{ return 2 * _nterms; }

getOrder()

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

inlineinherited

Returns the polynomial order.

Definition at line 309 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 215 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 ( const double  precision, const Frame &  region  ) const

virtual

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 1272 of file AstrometryTransform.cc.

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

inverted()

AstrometryTransformLinear lsst::jointcal::AstrometryTransformLinear::inverted

(

)

const

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

Definition at line 1245 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.");
        dump(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, const double  step = 0.01  ) const

virtual

linear (local) approximation.

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 1241 of file AstrometryTransform.cc.

                                                                                                          {
    return *this;
}

offsetParams()

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

inherited

Definition at line 220 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]

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

inherited

Composition (internal stuff in quadruple precision)

Definition at line 1035 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.coeff(px, py, 0) = rx.coeff(px, py);
            result.coeff(px, py, 1) = ry.coeff(px, py);
        }
    return result;
}

operator*() [2/2]

AstrometryTransformLinear lsst::jointcal::AstrometryTransformLinear::operator*

(

AstrometryTransformLinear const &

right

)

const

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

Definition at line 1219 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+()

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

inherited

Addition.

Definition at line 1057 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.coeff(i, j, 0) += right.coeff(i, j, 0);
                res.coeff(i, j, 1) += right.coeff(i, j, 1);
            }
        return res;
    } else
        return (right + (*this));
}

operator-()

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

inherited

Subtraction.

Definition at line 1071 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.coeff(i, j, 0) = coeffOrZero(i, j, 0) - right.coeffOrZero(i, j, 0);
            res.coeff(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 773 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 const  i ) const

overridevirtualinherited

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 763 of file AstrometryTransform.cc.

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

paramRef() [2/2]

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

overridevirtualinherited

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 768 of file AstrometryTransform.cc.

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

read()

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

inherited

Definition at line 1097 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::TanRaDecToPixel, lsst::jointcal::TanPixelToRaDec, and lsst::jointcal::AstrometryTransformInverse.

Definition at line 194 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 1082 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 161 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 654 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 245 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 1087 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);
}

Friends And Related Function Documentation

AstrometryTransform

friend class AstrometryTransform

friend

Definition at line 482 of file AstrometryTransform.h.

AstrometryTransformIdentity

friend class AstrometryTransformIdentity

friend

Definition at line 483 of file AstrometryTransform.h.

AstrometryTransformPolynomial

friend class AstrometryTransformPolynomial

friend

Definition at line 484 of file AstrometryTransform.h.

---

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

• /j/snowflake/release/lsstsw/stack/Linux64/jointcal/19.0.0-2-gb96a1c4+3/include/lsst/jointcal/AstrometryTransform.h
• /j/snowflake/release/lsstsw/stack/Linux64/jointcal/19.0.0-2-gb96a1c4+3/src/AstrometryTransform.cc