lsst.jointcal  15.0-11-gda8ddd7+3
Public Member Functions | List of all members
lsst::jointcal::Gtransfo Class Referenceabstract

a virtual (interface) class for geometric transformations. More...

#include <Gtransfo.h>

Inheritance diagram for lsst::jointcal::Gtransfo:
lsst::jointcal::BaseTanWcs lsst::jointcal::GtransfoComposition lsst::jointcal::GtransfoIdentity lsst::jointcal::GtransfoInverse lsst::jointcal::GtransfoPoly lsst::jointcal::GtransfoSkyWcs lsst::jointcal::TanRaDec2Pix lsst::jointcal::UserTransfo

Public Member Functions

virtual void apply (const double xIn, const double yIn, double &xOut, double &yOut) const =0
 
void apply (Point const &in, Point &out) const
 applies the tranfo to in and writes into out. Is indeed virtual. 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 dump (std::ostream &stream=std::cout) const =0
 dumps the transfo coefficients to stream. More...
 
std::string __str__ ()
 
virtual double fit (StarMatchList const &starMatchList)=0
 fits a transfo to a std::list of Point pairs (p1,p2, the Point fields in StarMatch). More...
 
void transformStar (FatPoint &in) const
 allows to write MyTransfo(MyStar) More...
 
virtual double getJacobian (Point const &point) const
 returns the local jacobian. More...
 
virtual std::unique_ptr< Gtransfoclone () const =0
 returns a copy (allocated by new) of the transformation. More...
 
virtual std::unique_ptr< GtransfocomposeAndReduce (Gtransfo const &right) const
 Return a reduced composition of newTransfo = this(right()), or nullptr if it cannot be reduced. More...
 
virtual double getJacobian (const double x, const double y) const
 returns the local jacobian. More...
 
virtual void computeDerivative (Point const &where, GtransfoLin &derivative, const double step=0.01) const
 Computes the local Derivative of a transfo, w.r.t. More...
 
virtual GtransfoLin 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...
 
virtual std::unique_ptr< GtransfoinverseTransfo (const double precision, const Frame &region) const
 returns an inverse transfo. Numerical if not overloaded. More...
 
void getParams (double *params) const
 params should be at least Npar() long More...
 
void offsetParams (Eigen::VectorXd const &delta)
 
virtual double paramRef (const int i) const
 
virtual double & paramRef (const int i)
 
virtual void paramDerivatives (Point const &where, double *dx, double *dy) const
 Derivative w.r.t parameters. More...
 
virtual std::unique_ptr< GtransforoughInverse (const Frame &region) const
 Rough inverse. More...
 
virtual int getNpar () const
 returns the number of parameters (to compute chi2's) More...
 
virtual std::shared_ptr< ast::MappingtoAstMap (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
 
virtual ~Gtransfo ()
 

Detailed Description

a virtual (interface) class for geometric transformations.

We implement here One Gtransfo interface class, and actual derived classes. Composition in the usual (mathematical) sense is provided using gtransfoCompose(), and some classes (e.g. GtransfoLin) handle a * operator. Generic inversion by iteration exists, but it is at least 10 times slower than the corresponding "direct transformation". If a transfo has an analytical inverse, then providing inverseTransfo is obviously a very good idea. Before resorting to inverseTransfo, consider using StarMatchList::inverseTransfo(). GtransfoLin::invert() and TanPix2RaDec::invert() exist. The classes also provide derivation and linear approximation.

Definition at line 42 of file Gtransfo.h.

Constructor & Destructor Documentation

◆ ~Gtransfo()

virtual lsst::jointcal::Gtransfo::~Gtransfo ( )
inlinevirtual

Definition at line 174 of file Gtransfo.h.

Member Function Documentation

◆ __str__()

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

Definition at line 71 of file Gtransfo.h.

◆ apply() [1/4]

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

◆ apply() [2/4]

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

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

Definition at line 48 of file Gtransfo.h.

◆ apply() [3/4]

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

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

Definition at line 52 of file Gtransfo.h.

◆ apply() [4/4]

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

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

Parameters
[in]inputframeThe frame to be transformed.
[in]inscribedReturn the inscribed (true) or circumscribed (false) box.
Returns
The transformed frame.

Definition at line 50 of file Gtransfo.cc.

◆ clone()

virtual std::unique_ptr<Gtransfo> lsst::jointcal::Gtransfo::clone ( ) const
pure virtual

◆ composeAndReduce()

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

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
rightThe 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 68 of file Gtransfo.cc.

◆ computeDerivative()

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

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

the Derivative is represented by a GtransfoLin, 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::GtransfoLin, lsst::jointcal::GtransfoPoly, and lsst::jointcal::GtransfoIdentity.

Definition at line 92 of file Gtransfo.cc.

◆ dump()

virtual void lsst::jointcal::Gtransfo::dump ( std::ostream stream = std::cout) const
pure virtual

◆ fit()

virtual double lsst::jointcal::Gtransfo::fit ( StarMatchList const &  starMatchList)
pure virtual

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

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

Implemented in lsst::jointcal::UserTransfo, lsst::jointcal::TanRaDec2Pix, lsst::jointcal::TanSipPix2RaDec, lsst::jointcal::TanPix2RaDec, lsst::jointcal::GtransfoSkyWcs, lsst::jointcal::GtransfoLinRot, lsst::jointcal::GtransfoLinShift, lsst::jointcal::GtransfoComposition, lsst::jointcal::GtransfoPoly, lsst::jointcal::GtransfoInverse, and lsst::jointcal::GtransfoIdentity.

◆ getJacobian() [1/2]

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

returns the local jacobian.

Definition at line 88 of file Gtransfo.h.

◆ getJacobian() [2/2]

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

returns the local jacobian.

Definition at line 73 of file Gtransfo.cc.

◆ getNpar()

virtual int lsst::jointcal::Gtransfo::getNpar ( ) const
inlinevirtual

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

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

Definition at line 157 of file Gtransfo.h.

◆ getParams()

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

params should be at least Npar() long

Definition at line 186 of file Gtransfo.cc.

◆ inverseTransfo()

std::unique_ptr< Gtransfo > lsst::jointcal::Gtransfo::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 in lsst::jointcal::TanRaDec2Pix, lsst::jointcal::TanSipPix2RaDec, lsst::jointcal::TanPix2RaDec, lsst::jointcal::GtransfoLin, and lsst::jointcal::GtransfoInverse.

Definition at line 268 of file Gtransfo.cc.

◆ linearApproximation()

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

linear (local) approximation.

Reimplemented in lsst::jointcal::GtransfoLin, and lsst::jointcal::GtransfoIdentity.

Definition at line 109 of file Gtransfo.cc.

◆ offsetParams()

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

Definition at line 191 of file Gtransfo.cc.

◆ paramDerivatives()

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

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::GtransfoPoly.

Definition at line 205 of file Gtransfo.cc.

◆ paramRef() [1/2]

double lsst::jointcal::Gtransfo::paramRef ( const int  i) const
virtual

Reimplemented in lsst::jointcal::GtransfoPoly.

Definition at line 196 of file Gtransfo.cc.

◆ paramRef() [2/2]

double & lsst::jointcal::Gtransfo::paramRef ( const int  i)
virtual

Reimplemented in lsst::jointcal::GtransfoPoly.

Definition at line 201 of file Gtransfo.cc.

◆ roughInverse()

std::unique_ptr< Gtransfo > lsst::jointcal::Gtransfo::roughInverse ( const Frame region) const
virtual

Rough inverse.

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

Reimplemented in lsst::jointcal::TanRaDec2Pix, lsst::jointcal::TanPix2RaDec, and lsst::jointcal::GtransfoInverse.

Definition at line 166 of file Gtransfo.cc.

◆ toAstMap()

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

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

Parameters
domainThe domain of the transfo, to help find an inverse.
Returns
An AST Mapping that represents this transformation.

Reimplemented in lsst::jointcal::GtransfoPoly, and lsst::jointcal::GtransfoIdentity.

Definition at line 166 of file Gtransfo.h.

◆ transformErrors()

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

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

Definition at line 133 of file Gtransfo.cc.

◆ transformPosAndErrors()

void lsst::jointcal::Gtransfo::transformPosAndErrors ( const FatPoint in,
FatPoint out 
) const
virtual

Reimplemented in lsst::jointcal::TanRaDec2Pix, and lsst::jointcal::GtransfoPoly.

Definition at line 116 of file Gtransfo.cc.

◆ transformStar()

void lsst::jointcal::Gtransfo::transformStar ( FatPoint in) const
inline

allows to write MyTransfo(MyStar)

Definition at line 85 of file Gtransfo.h.

◆ write() [1/2]

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

Definition at line 215 of file Gtransfo.cc.

◆ write() [2/2]

void lsst::jointcal::Gtransfo::write ( std::ostream stream) const
virtual

Reimplemented in lsst::jointcal::GtransfoPoly, and lsst::jointcal::GtransfoIdentity.

Definition at line 225 of file Gtransfo.cc.


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