lsst::jointcal::TanPixelToRaDec Class Reference

The transformation that handles pixels to sideral transformations (Gnomonic, possibly with polynomial distortions). More...

#include <AstrometryTransform.h>

Inheritance diagram for lsst::jointcal::TanPixelToRaDec:

Public Member Functions
	TanPixelToRaDec (AstrometryTransformLinear const &pixToTan, Point const &tangentPoint, const AstrometryTransformPolynomial *corrections=nullptr)
	pixToTan describes the transform from pix to tangent plane (degrees). More...
AstrometryTransformPolynomial	getPixelToTangentPlane () const
	the transformation from pixels to tangent plane (degrees) More...
virtual void	pixToTangentPlane (double xPixel, double yPixel, double &xTangentPlane, double &yTangentPlane) const
	transforms from pixel space to tangent plane (degrees) More...
	TanPixelToRaDec ()
TanPixelToRaDec	operator* (AstrometryTransformLinear const &right) const
	composition with AstrometryTransformLinear More...
std::unique_ptr< AstrometryTransform >	composeAndReduce (AstrometryTransformLinear const &right) const
	Return a reduced composition of newTransform = this(right()), or nullptr if it cannot be reduced. More...
TanRaDecToPixel	inverted () const
	approximate inverse : it ignores corrections; More...
std::unique_ptr< AstrometryTransform >	roughInverse (const Frame &region) const
	Overload the "generic routine" (available for all AstrometryTransform types. More...
std::unique_ptr< AstrometryTransform >	inverseTransform (const double precision, const Frame &region) const
	Inverse transform: returns a TanRaDecToPixel if there are no corrections, or the iterative solver if there are. More...
std::unique_ptr< AstrometryTransform >	clone () const
	returns a copy (allocated by new) of the transformation. More...
void	dump (std::ostream &stream) const
	dumps the transform coefficients to stream. More...
double	fit (StarMatchList const &starMatchList)
	Not implemented yet, because we do it otherwise. More...
void	apply (const double xIn, const double yIn, double &xOut, double &yOut) const
	Transform pixels to ICRS RA, Dec in degrees. More...
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...
Point	getTangentPoint () const
	Get the sky origin (CRVAL in FITS WCS terminology) in degrees. More...
AstrometryTransformLinear	getLinPart () const
	The Linear part (corresponding to CD's and CRPIX's) More...
const AstrometryTransformPolynomial *	getCorr () const
	Get a non-owning pointer to the correction transform polynomial. More...
void	setCorrections (std::unique_ptr< AstrometryTransformPolynomial > corrections)
	Assign the correction polynomial (what it means is left to derived classes) More...
Point	getCrPix () const
	Get the pixel origin of the WCS (CRPIX in FITS WCS terminology, but zero-based) More...
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 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...
virtual void	computeDerivative (Point const &where, AstrometryTransformLinear &derivative, const double step=0.01) const
	Computes the local Derivative of a transform, w.r.t. More...
virtual AstrometryTransformLinear	linearApproximation (Point const &where, const double step=0.01) const
	linear (local) approximation. More...
virtual void	transformPosAndErrors (const FatPoint &in, FatPoint &out) const
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 double	paramRef (Eigen::Index const i) const
virtual double &	paramRef (Eigen::Index const i)
virtual void	paramDerivatives (Point const &where, double *dx, double *dy) const
	Derivative w.r.t parameters. More...
virtual std::size_t	getNpar () const
	returns the number of parameters (to compute chi2's) More...
virtual std::shared_ptr< ast::Mapping >	toAstMap (jointcal::Frame const &domain) const
	Create an equivalent AST mapping for this transformation, including an analytic inverse if possible. More...
void	write (const std::string &fileName) const
virtual void	write (std::ostream &stream) const

Protected Attributes
AstrometryTransformLinear	linPixelToTan
std::unique_ptr< AstrometryTransformPolynomial >	corr
double	ra0
double	dec0
double	cos0
double	sin0

Detailed Description

The transformation that handles pixels to sideral transformations (Gnomonic, possibly with polynomial distortions).

Definition at line 623 of file AstrometryTransform.h.

Constructor & Destructor Documentation

TanPixelToRaDec() [1/2]

lsst::jointcal::TanPixelToRaDec::TanPixelToRaDec	(	AstrometryTransformLinear const &	pixToTan,
		Point const &	tangentPoint,
		const AstrometryTransformPolynomial *	corrections = nullptr
	)

pixToTan describes the transform from pix to tangent plane (degrees).

TangentPoint in degrees. Corrections are applied between Lin and deprojection parts (as in Swarp).

Definition at line 1468 of file AstrometryTransform.cc.

        : BaseTanWcs(pixToTan, tangentPoint, corrections) {}

TanPixelToRaDec() [2/2]

lsst::jointcal::TanPixelToRaDec::TanPixelToRaDec

(

)

Definition at line 1473 of file AstrometryTransform.cc.

: BaseTanWcs(AstrometryTransformLinear(), Point(0, 0), nullptr) {}

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();
    }

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::BaseTanWcs::apply ( const double  xIn, const double  yIn, double &  xOut, double &  yOut  ) const

virtualinherited

Transform pixels to ICRS RA, Dec in degrees.

Implements lsst::jointcal::AstrometryTransform.

Definition at line 1397 of file AstrometryTransform.cc.

                                                                                           {
    double l, m;                        // radians in the tangent plane
    pixToTangentPlane(xIn, yIn, l, m);  // l, m in degrees.
    l = deg2rad(l);
    m = deg2rad(m);  // now in radians
                     // Code inspired from worldpos.c in wcssubs (ancestor of the wcslib)
                     /* At variance with wcslib, it collapses the projection to a plane
                        and expression of sidereal cooordinates into a single set of
                        operations. */
    double dect = cos0 - m * sin0;
    if (dect == 0) {
        LOGL_WARN(_log, "No sidereal coordinates at pole!");
        xOut = 0;
        yOut = 0;
        return;
    }
    double rat = ra0 + atan2(l, dect);
    dect = atan(std::cos(rat - ra0) * (m * cos0 + sin0) / dect);
    if (rat - ra0 > M_PI) rat -= (2. * M_PI);
    if (rat - ra0 < -M_PI) rat += (2. * M_PI);
    if (rat < 0.0) rat += (2. * M_PI);
    // convert to degree
    xOut = rad2deg(rat);
    yOut = rad2deg(dect);
}

clone()

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

virtual

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

Implements lsst::jointcal::AstrometryTransform.

Definition at line 1530 of file AstrometryTransform.cc.

                                                                {
    return std::unique_ptr<AstrometryTransform>(
            new TanPixelToRaDec(getLinPart(), getTangentPoint(), corr.get()));
}

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::TanPixelToRaDec::composeAndReduce

(

AstrometryTransformLinear const &

right

)

const

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 1475 of file AstrometryTransform.cc.

                                                      {
    if (right.getOrder() == 1) {
        return std::make_unique<TanPixelToRaDec>((*this) * (right));
    } else {
        return std::unique_ptr<AstrometryTransform>(nullptr);
    }
}

computeDerivative()

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

virtualinherited

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 in lsst::jointcal::AstrometryTransformLinear, lsst::jointcal::AstrometryTransformPolynomial, and lsst::jointcal::AstrometryTransformIdentity.

Definition at line 117 of file AstrometryTransform.cc.

                                                                     {
    double x = where.x;
    double y = where.y;
    double xp0, yp0;
    apply(x, y, xp0, yp0);

    double xp, yp;
    apply(x + step, y, xp, yp);
    derivative.a11() = (xp - xp0) / step;
    derivative.a21() = (yp - yp0) / step;
    apply(x, y + step, xp, yp);
    derivative.a12() = (xp - xp0) / step;
    derivative.a22() = (yp - yp0) / step;
    derivative.dx() = 0;
    derivative.dy() = 0;
}

dump()

void lsst::jointcal::TanPixelToRaDec::dump ( std::ostream &  stream ) const

virtual

dumps the transform coefficients to stream.

Implements lsst::jointcal::AstrometryTransform.

Definition at line 1535 of file AstrometryTransform.cc.

                                                {
    stream << " TanPixelToRaDec, lin part :" << endl << linPixelToTan;
    Point tp = getTangentPoint();
    stream << " tangent point " << tp.x << ' ' << tp.y << endl;
    Point crpix = getCrPix();
    stream << " crpix " << crpix.x << ' ' << crpix.y << endl;
    if (corr) stream << "PV correction: " << endl << *corr;
}

fit()

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

virtual

Not implemented yet, because we do it otherwise.

Implements lsst::jointcal::AstrometryTransform.

Definition at line 1544 of file AstrometryTransform.cc.

                                                 {
    /* OK we could implement this routine, but it is
       probably useless since to do the match, we have to
       project from sky to tangent plane. When a match is
       found, it is easier to carry out the fit in the
       tangent plane, rather than going back to the celestial
       sphere (and reproject to fit...). Anyway if this
       message shows up, we'll think about it.
    */
    throw LSST_EXCEPT(pex::exceptions::InvalidParameterError,
                      "TanPixelToRaDec::fit is NOT implemented (although it is doable)) ");
    return -1;
}

getCorr()

const AstrometryTransformPolynomial* lsst::jointcal::BaseTanWcs::getCorr ( ) const

inlineinherited

Get a non-owning pointer to the correction transform polynomial.

Definition at line 591 of file AstrometryTransform.h.

{ return corr.get(); }

getCrPix()

Point lsst::jointcal::BaseTanWcs::getCrPix ( ) const

inherited

Get the pixel origin of the WCS (CRPIX in FITS WCS terminology, but zero-based)

Definition at line 1431 of file AstrometryTransform.cc.

                                 {
    /* CRPIX's are defined by:
                      ( CD1_1  CD1_2 )   (x - crpix1)
       transformed =  (              ) * (          )
                      ( CD2_1  CD2_2 )   (y - crpix2)

       so that CrPix is the point which transforms to (0,0)
    */
    const AstrometryTransformLinear inverse = linPixelToTan.inverted();
    return Point(inverse.Dx(), inverse.Dy());
}

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));
}

getLinPart()

AstrometryTransformLinear lsst::jointcal::BaseTanWcs::getLinPart ( ) const

inherited

The Linear part (corresponding to CD's and CRPIX's)

Definition at line 1425 of file AstrometryTransform.cc.

{ return linPixelToTan; }

getNpar()

virtual std::size_t lsst::jointcal::AstrometryTransform::getNpar ( ) const

inlinevirtualinherited

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

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

Definition at line 180 of file AstrometryTransform.h.

{ return 0; }

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);
}

getPixelToTangentPlane()

AstrometryTransformPolynomial lsst::jointcal::TanPixelToRaDec::getPixelToTangentPlane ( ) const

virtual

the transformation from pixels to tangent plane (degrees)

Implements lsst::jointcal::BaseTanWcs.

Definition at line 1512 of file AstrometryTransform.cc.

                                                                            {
    if (corr)
        return (*corr) * linPixelToTan;
    else
        return linPixelToTan;
}

getTangentPoint()

Point lsst::jointcal::BaseTanWcs::getTangentPoint ( ) const

inherited

Get the sky origin (CRVAL in FITS WCS terminology) in degrees.

Definition at line 1423 of file AstrometryTransform.cc.

{ return Point(rad2deg(ra0), rad2deg(dec0)); }

inverseTransform()

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

virtual

Inverse transform: returns a TanRaDecToPixel if there are no corrections, or the iterative solver if there are.

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 1503 of file AstrometryTransform.cc.

                                                                                                  {
    if (!corr)
        return std::unique_ptr<AstrometryTransform>(
                new TanRaDecToPixel(getLinPart().inverted(), getTangentPoint()));
    else
        return std::unique_ptr<AstrometryTransform>(new AstrometryTransformInverse(this, precision, region));
}

inverted()

TanRaDecToPixel lsst::jointcal::TanPixelToRaDec::inverted

(

)

const

approximate inverse : it ignores corrections;

Definition at line 1490 of file AstrometryTransform.cc.

                                                {
    if (corr != nullptr) {
        LOGL_WARN(_log, "You are inverting a TanPixelToRaDec with corrections.");
        LOGL_WARN(_log, "The inverse you get ignores the corrections!");
    }
    return TanRaDecToPixel(getLinPart().inverted(), getTangentPoint());
}

linearApproximation()

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

virtualinherited

linear (local) approximation.

Reimplemented in lsst::jointcal::AstrometryTransformLinear, and lsst::jointcal::AstrometryTransformIdentity.

Definition at line 135 of file AstrometryTransform.cc.

                                                                                            {
    Point outwhere = apply(where);
    AstrometryTransformLinear der;
    computeDerivative(where, der, step);
    return AstrometryTransformLinearShift(outwhere.x, outwhere.y) * der *
           AstrometryTransformLinearShift(-where.x, -where.y);
}

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*()

TanPixelToRaDec lsst::jointcal::TanPixelToRaDec::operator*

(

AstrometryTransformLinear const &

right

)

const

composition with AstrometryTransformLinear

Definition at line 1484 of file AstrometryTransform.cc.

                                                                                       {
    TanPixelToRaDec result(*this);
    result.linPixelToTan = result.linPixelToTan * right;
    return result;
}

paramDerivatives()

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

virtualinherited

Derivative w.r.t parameters.

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

Reimplemented in lsst::jointcal::AstrometryTransformPolynomial.

Definition at line 235 of file AstrometryTransform.cc.

                                                                                  {
    throw LSST_EXCEPT(pex::exceptions::InvalidParameterError,
                      "AstrometryTransform::paramDerivatives() should never be called ");
}

paramRef() [1/2]

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

virtualinherited

Reimplemented in lsst::jointcal::AstrometryTransformPolynomial.

Definition at line 225 of file AstrometryTransform.cc.

                                                           {
    throw LSST_EXCEPT(pex::exceptions::InvalidParameterError,
                      std::string("AstrometryTransform::paramRef should never be called "));
}

paramRef() [2/2]

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

virtualinherited

Reimplemented in lsst::jointcal::AstrometryTransformPolynomial.

Definition at line 230 of file AstrometryTransform.cc.

                                                      {
    throw LSST_EXCEPT(pex::exceptions::InvalidParameterError,
                      "AstrometryTransform::paramRef should never be called ");
}

pixToTangentPlane()

void lsst::jointcal::TanPixelToRaDec::pixToTangentPlane ( double  xPixel, double  yPixel, double &  xTangentPlane, double &  yTangentPlane  ) const

virtual

transforms from pixel space to tangent plane (degrees)

Implements lsst::jointcal::BaseTanWcs.

Definition at line 1519 of file AstrometryTransform.cc.

                                                                     {
    // xTangentPlane, yTangentPlane in degrees.
    linPixelToTan.apply(xPixel, yPixel, xTangentPlane, yTangentPlane);
    if (corr) {
        double xtmp = xTangentPlane;
        double ytmp = yTangentPlane;
        corr->apply(xtmp, ytmp, xTangentPlane, yTangentPlane);  // still in degrees.
    }
}

roughInverse()

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

virtual

Overload the "generic routine" (available for all AstrometryTransform types.

Reimplemented from lsst::jointcal::AstrometryTransform.

Definition at line 1498 of file AstrometryTransform.cc.

                                                                                    {
    return std::unique_ptr<AstrometryTransform>(
            new TanRaDecToPixel(getLinPart().inverted(), getTangentPoint()));
}

setCorrections()

void lsst::jointcal::BaseTanWcs::setCorrections ( std::unique_ptr< AstrometryTransformPolynomial >  corrections )

inherited

Assign the correction polynomial (what it means is left to derived classes)

Definition at line 1427 of file AstrometryTransform.cc.

                                                                                        {
    corr = std::move(corrections);
}

toAstMap()

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

inlinevirtualinherited

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 in lsst::jointcal::AstrometryTransformPolynomial, and lsst::jointcal::AstrometryTransformIdentity.

Definition at line 189 of file AstrometryTransform.h.

                                                                                  {
        throw std::logic_error("toAstMap is not implemented for this class.");
    }

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::AstrometryTransform::transformPosAndErrors ( const FatPoint &  in, FatPoint &  out  ) const

virtualinherited

Reimplemented in lsst::jointcal::TanRaDecToPixel, and lsst::jointcal::AstrometryTransformPolynomial.

Definition at line 144 of file AstrometryTransform.cc.

                                                                                       {
    FatPoint res;  // in case in and out are the same address...
    res = apply(in);
    AstrometryTransformLinear der;
    // could save a call here, since Derivative needs the transform of where that we already have
    // 0.01 may not be a very good idea in all cases. May be we should provide a way of altering that.
    computeDerivative(in, der, 0.01);
    double a11 = der.A11();
    double a22 = der.A22();
    double a21 = der.A21();
    double a12 = der.A12();
    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::AstrometryTransform::write ( std::ostream &  stream ) const

virtualinherited

Reimplemented in lsst::jointcal::AstrometryTransformPolynomial, and lsst::jointcal::AstrometryTransformIdentity.

Definition at line 255 of file AstrometryTransform.cc.

                                                     {
    throw LSST_EXCEPT(
            pex::exceptions::InvalidParameterError,
            "AstrometryTransform::write(ostream), should never be called. MEans that it is missing in some "
            "derived class ");
}

Member Data Documentation

corr

std::unique_ptr<AstrometryTransformPolynomial> lsst::jointcal::BaseTanWcs::corr

protectedinherited

Definition at line 612 of file AstrometryTransform.h.

cos0

double lsst::jointcal::BaseTanWcs::cos0

protectedinherited

Definition at line 614 of file AstrometryTransform.h.

dec0

double lsst::jointcal::BaseTanWcs::dec0

protectedinherited

Definition at line 613 of file AstrometryTransform.h.

linPixelToTan

AstrometryTransformLinear lsst::jointcal::BaseTanWcs::linPixelToTan

protectedinherited

Definition at line 610 of file AstrometryTransform.h.

ra0

double lsst::jointcal::BaseTanWcs::ra0

protectedinherited

Definition at line 613 of file AstrometryTransform.h.

sin0

double lsst::jointcal::BaseTanWcs::sin0

protectedinherited

Definition at line 614 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