lsst::jointcal::GtransfoLin Class Reference

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

#include <Gtransfo.h>

Inheritance diagram for lsst::jointcal::GtransfoLin:

Public Member Functions
	GtransfoLin ()
	the default constructor constructs the do-nothing transformation. More...
	GtransfoLin (GtransfoPoly const &gtransfoPoly)
	This triggers an exception if P.getOrder() != 1. More...
GtransfoLin	operator* (GtransfoLin const &right) const
	enables to combine linear tranformations: T1=T2*T3 is legal. More...
GtransfoLin	inverted () const
	returns the inverse: T1 = T2.inverted(); More...
void	computeDerivative (Point const &where, GtransfoLin &derivative, const double step=0.01) const
	specialised analytic routine More...
GtransfoLin	linearApproximation (Point const &where, const double step=0.01) const
	linear (local) approximation. More...
	GtransfoLin (const double ox, const double oy, const double aa11, const double aa12, const double aa21, const double aa22)
	Construct a GtransfoLin from parameters. More...
	GtransfoLin (GtransfoIdentity const &)
	Handy converter: More...
std::unique_ptr< Gtransfo >	clone () const
	returns a copy (allocated by new) of the transformation. More...
std::unique_ptr< Gtransfo >	inverseTransfo (const double precision, const Frame &region) const
	returns an inverse transfo. Numerical if not overloaded. More...
double	A11 () const
double	A12 () const
double	A21 () const
double	A22 () const
double	Dx () const
double	Dy () const
unsigned	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 Gtransfo::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...
int	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...
GtransfoPoly	operator* (GtransfoPoly const &right) const
	Composition (internal stuff in quadruple precision) More...
GtransfoPoly	operator+ (GtransfoPoly const &right) const
	Addition. More...
GtransfoPoly	operator- (GtransfoPoly const &right) const
	Subtraction. More...
std::unique_ptr< Gtransfo >	composeAndReduce (GtransfoPoly const &right) const
	Return a reduced composition of newTransfo = this(right()), or nullptr if it cannot be reduced. More...
virtual std::unique_ptr< Gtransfo >	composeAndReduce (Gtransfo const &right) const
	Return a reduced composition of newTransfo = this(right()), or nullptr if it cannot be reduced. More...
double	coeff (const unsigned powX, const unsigned powY, const unsigned whichCoord) const
	access to coefficients (read only) More...
double &	coeff (const unsigned powX, const unsigned powY, const unsigned whichCoord)
	write access More...
double	coeffOrZero (const unsigned powX, const unsigned powY, const unsigned whichCoord) const
	read access, zero if beyond order More...
double	determinant () const
double	paramRef (const int i) const override
double &	paramRef (const int 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
	allows to write MyTransfo(MyStar) More...
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< Gtransfo >	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	Gtransfo
class	GtransfoIdentity
class	GtransfoPoly

Detailed Description

implements the linear transformations (6 real coefficients).

Definition at line 414 of file Gtransfo.h.

Constructor & Destructor Documentation

GtransfoLin() [1/4]

lsst::jointcal::GtransfoLin::GtransfoLin ( )

inline

the default constructor constructs the do-nothing transformation.

Definition at line 419 of file Gtransfo.h.

: GtransfoPoly(1){};

GtransfoLin() [2/4]

lsst::jointcal::GtransfoLin::GtransfoLin ( GtransfoPoly const &  gtransfoPoly )

explicit

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

Definition at line 1172 of file Gtransfo.cc.

                                                         : GtransfoPoly(1) {
    if (gtransfoPoly.getOrder() != 1)
        throw pexExcept::InvalidParameterError(
                "Trying to build a GtransfoLin from a higher order transfo. Aborting. ");
    (GtransfoPoly &)(*this) = gtransfoPoly;
}

GtransfoLin() [3/4]

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

Construct a GtransfoLin from parameters.

Definition at line 1161 of file Gtransfo.cc.

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

GtransfoLin() [4/4]

lsst::jointcal::GtransfoLin::GtransfoLin ( GtransfoIdentity const &  )

inline

Handy converter:

Definition at line 446 of file Gtransfo.h.

: GtransfoPoly(1){};

Member Function Documentation

__str__()

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

inlineinherited

Definition at line 94 of file Gtransfo.h.

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

A11()

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

inline

Definition at line 452 of file Gtransfo.h.

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

a11()

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

inlineprotected

Definition at line 460 of file Gtransfo.h.

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

A12()

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

inline

Definition at line 453 of file Gtransfo.h.

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

a12()

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

inlineprotected

Definition at line 461 of file Gtransfo.h.

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

A21()

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

inline

Definition at line 454 of file Gtransfo.h.

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

a21()

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

inlineprotected

Definition at line 462 of file Gtransfo.h.

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

A22()

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

inline

Definition at line 455 of file Gtransfo.h.

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

a22()

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

inlineprotected

Definition at line 463 of file Gtransfo.h.

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

apply() [1/4]

void lsst::jointcal::Gtransfo::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 Gtransfo.h.

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

apply() [2/4]

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

inlineinherited

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

Definition at line 75 of file Gtransfo.h.

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

apply() [3/4]

Frame lsst::jointcal::Gtransfo::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 74 of file Gtransfo.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::GtransfoPoly::apply ( const double  xIn, const double  yIn, double &  xOut, double &  yOut  ) const

overridevirtualinherited

Implements lsst::jointcal::Gtransfo.

Definition at line 546 of file Gtransfo.cc.

                                                                                             {
    /*
      This routine computes the monomials only once for both
      polynomials.  This is why GtransfoPoly 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<Gtransfo> lsst::jointcal::GtransfoLin::clone ( ) const

inlinevirtual

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

Reimplemented from lsst::jointcal::GtransfoPoly.

Definition at line 448 of file Gtransfo.h.

{ return std::unique_ptr<Gtransfo>(new GtransfoLin(*this)); }

coeff() [1/2]

double lsst::jointcal::GtransfoPoly::coeff ( const unsigned  powX, const unsigned  powY, const unsigned  whichCoord  ) const

inherited

access to coefficients (read only)

Definition at line 711 of file Gtransfo.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::GtransfoPoly::coeff ( const unsigned  powX, const unsigned  powY, const unsigned  whichCoord  )

inherited

write access

Definition at line 719 of file Gtransfo.cc.

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

coeffOrZero()

double lsst::jointcal::GtransfoPoly::coeffOrZero ( const unsigned  powX, const unsigned  powY, const unsigned  whichCoord  ) const

inherited

read access, zero if beyond order

Definition at line 724 of file Gtransfo.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< Gtransfo > lsst::jointcal::Gtransfo::composeAndReduce ( Gtransfo const &  right ) const

virtualinherited

Return a reduced composition of newTransfo = 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 gtransfo, or nullptr if no such reduction is possible.

Reimplemented in lsst::jointcal::GtransfoIdentity.

Definition at line 92 of file Gtransfo.cc.

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

composeAndReduce() [2/2]

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

inherited

Return a reduced composition of newTransfo = 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 gtransfo, or nullptr if no such reduction is possible.

Definition at line 898 of file Gtransfo.cc.

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

computeDerivative()

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

virtual

specialised analytic routine

Reimplemented from lsst::jointcal::GtransfoPoly.

Definition at line 1194 of file Gtransfo.cc.

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

determinant()

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

inherited

Definition at line 782 of file Gtransfo.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::GtransfoPoly::dump ( std::ostream &  stream = std::cout ) const

overridevirtualinherited

print out of coefficients in a readable form.

Implements lsst::jointcal::Gtransfo.

Definition at line 763 of file Gtransfo.cc.

                                             {
    auto oldPrecision = stream.precision();
    stream.precision(12);
    for (unsigned ic = 0; ic < 2; ++ic) {
        if (ic == 0)
            stream << "newx = ";
        else
            stream << "newy = ";
        for (unsigned p = 0; p <= _order; ++p)
            for (unsigned 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::GtransfoLin::Dx ( ) const

inline

Definition at line 456 of file Gtransfo.h.

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

dx()

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

inlineprotected

Definition at line 464 of file Gtransfo.h.

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

Dy()

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

inline

Definition at line 457 of file Gtransfo.h.

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

dy()

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

inlineprotected

Definition at line 465 of file Gtransfo.h.

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

fit()

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

overridevirtualinherited

guess what

Implements lsst::jointcal::Gtransfo.

Reimplemented in lsst::jointcal::GtransfoLinRot, and lsst::jointcal::GtransfoLinShift.

Definition at line 880 of file Gtransfo.cc.

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

    GtransfoPoly 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::Gtransfo::getJacobian ( Point const &  point ) const

inlinevirtualinherited

returns the local jacobian.

Definition at line 111 of file Gtransfo.h.

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

getJacobian() [2/2]

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

virtualinherited

returns the local jacobian.

Definition at line 97 of file Gtransfo.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()

int lsst::jointcal::GtransfoPoly::getNpar ( ) const

inlineoverridevirtualinherited

total number of parameters

Reimplemented from lsst::jointcal::Gtransfo.

Reimplemented in lsst::jointcal::GtransfoLinScale, lsst::jointcal::GtransfoLinRot, and lsst::jointcal::GtransfoLinShift.

Definition at line 316 of file Gtransfo.h.

{ return 2 * _nterms; }

getOrder()

unsigned lsst::jointcal::GtransfoPoly::getOrder ( ) const

inlineinherited

Returns the polynomial order.

Definition at line 302 of file Gtransfo.h.

{ return _order; }

getParams()

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

inherited

params should be at least Npar() long

Definition at line 210 of file Gtransfo.cc.

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

inverseTransfo()

std::unique_ptr< Gtransfo > lsst::jointcal::GtransfoLin::inverseTransfo ( const double  precision, const Frame &  region  ) const

virtual

returns an inverse transfo. Numerical if not overloaded.

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

Reimplemented from lsst::jointcal::Gtransfo.

Definition at line 1228 of file Gtransfo.cc.

                                                                                     {
    return std::unique_ptr<Gtransfo>(new GtransfoLin(inverted()));
}

inverted()

GtransfoLin lsst::jointcal::GtransfoLin::inverted

(

)

const

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

Definition at line 1202 of file Gtransfo.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,
                   "GtransfoLin::invert singular transformation: transfo contents will be dumped to stderr.");
        dump(cerr);
    }

    GtransfoLin 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()

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

virtual

linear (local) approximation.

Reimplemented from lsst::jointcal::Gtransfo.

Definition at line 1200 of file Gtransfo.cc.

{ return *this; }

offsetParams()

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

inherited

Definition at line 215 of file Gtransfo.cc.

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

operator*() [1/2]

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

inherited

Composition (internal stuff in quadruple precision)

Definition at line 1003 of file Gtransfo.cc.

                                                                    {
    // split each transfo 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.
    GtransfoPoly result(_order * right._order);
    for (unsigned px = 0; px <= result._order; ++px)
        for (unsigned 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]

GtransfoLin lsst::jointcal::GtransfoLin::operator*

(

GtransfoLin const &

right

)

const

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

Definition at line 1179 of file Gtransfo.cc.

                                                                 {
    // There is a general routine in GtransfoPoly that would do the job:
    //  return GtransfoLin(GtransfoPoly::operator*(right));
    // however, we are using this composition of linear stuff heavily in
    // Gtransfo::linearApproximation, itself used in inverseTransfo::apply.
    // So, for sake of efficiency, and since it is easy, we take a shortcut:
    GtransfoLin 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+()

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

inherited

Addition.

Definition at line 1024 of file Gtransfo.cc.

                                                                    {
    if (_order >= right._order) {
        GtransfoPoly res(*this);
        for (unsigned i = 0; i <= right._order; ++i)
            for (unsigned 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-()

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

inherited

Subtraction.

Definition at line 1037 of file Gtransfo.cc.

                                                                    {
    GtransfoPoly res(std::max(_order, right._order));
    for (unsigned i = 0; i <= res._order; ++i)
        for (unsigned 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::GtransfoPoly::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::Gtransfo.

Definition at line 743 of file Gtransfo.cc.

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

paramRef() [1/2]

double lsst::jointcal::GtransfoPoly::paramRef ( const int  i ) const

overridevirtualinherited

Reimplemented from lsst::jointcal::Gtransfo.

Definition at line 733 of file Gtransfo.cc.

                                               {
    assert(unsigned(i) < 2 * _nterms);
    return _coeffs[i];
}

paramRef() [2/2]

double & lsst::jointcal::GtransfoPoly::paramRef ( const int  i )

overridevirtualinherited

Reimplemented from lsst::jointcal::Gtransfo.

Definition at line 738 of file Gtransfo.cc.

                                          {
    assert(unsigned(i) < 2 * _nterms);
    return _coeffs[i];
}

read()

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

inherited

Definition at line 1062 of file Gtransfo.cc.

                                  {
    int format;
    s >> format;
    if (format != 1)
        throw LSST_EXCEPT(pex::exceptions::InvalidParameterError, " GtransfoPoly::read : format is not 1 ");

    string order;
    s >> order >> _order;
    if (order != "order")
        throw LSST_EXCEPT(pex::exceptions::InvalidParameterError,
                          " GtransfoPoly::read : expecting \"order\" and found " + order);
    setOrder(_order);
    for (unsigned k = 0; k < 2 * _nterms; ++k) s >> _coeffs[k];
}

roughInverse()

std::unique_ptr< Gtransfo > lsst::jointcal::Gtransfo::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::GtransfoInverse.

Definition at line 190 of file Gtransfo.cc.

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

toAstMap()

std::shared_ptr< ast::Mapping > lsst::jointcal::GtransfoPoly::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 transfo, to help find an inverse.

Returns

An AST Mapping that represents this transformation.

Reimplemented from lsst::jointcal::Gtransfo.

Definition at line 1047 of file Gtransfo.cc.

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

transformErrors()

void lsst::jointcal::Gtransfo::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 157 of file Gtransfo.cc.

                                                                                        {
    GtransfoLin 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::GtransfoPoly::transformPosAndErrors ( const FatPoint &  in, FatPoint &  out  ) const

overridevirtualinherited

a mix of apply and Derivative

Reimplemented from lsst::jointcal::Gtransfo.

Definition at line 627 of file Gtransfo.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
       Gtransfo::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 Gtransfo).  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 (unsigned ix = 0; ix <= _order; ++ix) {
        unsigned 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 (unsigned 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::Gtransfo::transformStar ( FatPoint &  in ) const

inlineinherited

allows to write MyTransfo(MyStar)

Definition at line 108 of file Gtransfo.h.

{ transformPosAndErrors(in, in); }

write() [1/2]

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

inherited

Definition at line 239 of file Gtransfo.cc.

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

write() [2/2]

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

overridevirtualinherited

Reimplemented from lsst::jointcal::Gtransfo.

Definition at line 1052 of file Gtransfo.cc.

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

Friends And Related Function Documentation

Gtransfo

friend class Gtransfo

friend

Definition at line 467 of file Gtransfo.h.

GtransfoIdentity

friend class GtransfoIdentity

friend

Definition at line 468 of file Gtransfo.h.

GtransfoPoly

friend class GtransfoPoly

friend

Definition at line 469 of file Gtransfo.h.

---

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

• /j/snowflake/release/lsstsw/stack/Linux64/jointcal/16.0-25-g07af9f2+1/include/lsst/jointcal/Gtransfo.h
• /j/snowflake/release/lsstsw/stack/Linux64/jointcal/16.0-25-g07af9f2+1/src/Gtransfo.cc