ast::Mapping Class Reference

An abstract base class for objects which transform one set of coordinates to another. More...

#include <Mapping.h>

Inheritance diagram for ast::Mapping:

Public Types
using	ObjectPtr = std::unique_ptr<AstObject, Deleter>
	unique pointer holding an AST raw pointer

Public Member Functions
virtual	~Mapping ()
	Mapping (Mapping const &)=default
	Copy constructor: make a deep copy.
	Mapping (Mapping &&)=default
Mapping &	operator= (Mapping const &)=delete
Mapping &	operator= (Mapping &&)=default
std::shared_ptr< Mapping >	copy () const
	Return a deep copy of this object.
int	getNIn () const
	Get NIn: the number of input axes.
int	getNOut () const
	Get NOut: the number of output axes.
bool	getIsSimple () const
	Get IsSimple: has the mapping been simplified?
bool	isInverted () const
	Is this an inverted mapping?
bool	getIsLinear () const
	Get IsLinear: is the Mapping linear?
bool	getReport () const
	Get Report: report transformed coordinates to stdout?
bool	hasForward () const
	Is the forward transform available?
bool	hasInverse () const
	Is the inverse transform available?
std::shared_ptr< Mapping >	inverted () const
	Get an inverse mapping.
Array2D	linearApprox (PointD const &lbnd, PointD const &ubnd, double tol) const
	Compute a linear approximation to the forward transformation.
SeriesMap	then (Mapping const &next) const
	Return a series compound mapping this(first(input)) containing shallow copies of the original.
ParallelMap	under (Mapping const &next) const
	Return a parallel compound mapping containing shallow copies of the original.
double	rate (PointD const &at, int ax1, int ax2) const
	Evaluate the rate of change of the Mapping with respect to a specified input, at a specified position.
void	setReport (bool report)
	Set Report: report transformed coordinates to stdout?
std::shared_ptr< Mapping >	simplified () const
	Return a simplied version of the mapping (which may be a compound Mapping such as a CmpMap).
void	applyForward (ConstArray2D const &from, Array2D const &to) const
	Perform a forward transformation on 2-D array, putting the results into a pre-allocated 2-D array.
Array2D	applyForward (ConstArray2D const &from) const
	Perform a forward transformation on a 2-D array, returning the results as a new array.
std::vector< double >	applyForward (std::vector< double > const &from) const
	Perform a forward transformation on a vector, returning the results as a new vector.
void	applyInverse (ConstArray2D const &from, Array2D const &to) const
	Perform an inverse transformation on a 2-D array, putting the results into a pre-allocated 2-D array.
Array2D	applyInverse (ConstArray2D const &from) const
	Perform an inverse transformation on a 2-D array, returning the results as a new 2-D array.
std::vector< double >	applyInverse (std::vector< double > const &from) const
	Perform an inverse transformation on a vector, returning the results as a new vector.
void	tranGridForward (PointI const &lbnd, PointI const &ubnd, double tol, int maxpix, Array2D const &to) const
	Transform a grid of points in the forward direction.
Array2D	tranGridForward (PointI const &lbnd, PointI const &ubnd, double tol, int maxpix, int nPts) const
	Transform a grid of points in the inverse direction, returning the results as a new Array2D.
void	tranGridInverse (PointI const &lbnd, PointI const &ubnd, double tol, int maxpix, Array2D const &to) const
	Transform a grid of points in the inverse direction.
Array2D	tranGridInverse (PointI const &lbnd, PointI const &ubnd, double tol, int maxpix, int nPts) const
	Transform a grid of points in the inverse direction.
bool	operator== (Object const &rhs) const
	Return True if this and rhs are the equal.
bool	operator!= (Object const &rhs) const
	Return True if this and rhs are not equal.
void	clear (std::string const &attrib)
	Clear the values of a specified set of attributes for an Object.
bool	hasAttribute (std::string const &attrib) const
	Does this object have an attribute with the specified name?
std::string	getClassName () const
	Get Class: the name of the class (e.g.
std::string	getID () const
	Get ID: object identification string that is not copied.
std::string	getIdent () const
	Get Ident: object identification string that is copied.
int	getNObject () const
	Get NObject: number of AST objects in existence of the same type as the underlying AST class.
int	getObjSize () const
	Get ObjSize: the in-memory size of the AST object in bytes.
int	getRefCount () const
	Get RefCount: number of active pointers to the underlying AST object.
bool	getUseDefs () const
	Get UseDefs: allow use of default values for Object attributes?
void	lock (bool wait)
	Lock this object for exclusive use by the calling thread.
bool	same (Object const &other) const
	Does this contain the same AST object as another?
void	setID (std::string const &id)
	Set ID: object identification string that is not copied.
void	setIdent (std::string const &ident)
	Set Ident: object identification string that is copied.
void	setUseDefs (bool usedefs)
	Set UseDefs: allow use of default values for Object attributes?
void	show (std::ostream &os, bool showComments=true) const
	Print a textual description the object to an ostream.
std::string	show (bool showComments=true) const
	Return a textual description the object as a string.
bool	test (std::string const &attrib) const
	Has this attribute been explicitly set (and not subsequently cleared)?
void	unlock (bool report=false)
	Unlock this object previously locked using lock, so that other threads can use this object.
AstObject const *	getRawPtr () const
	Get the raw AST pointer.
AstObject *	getRawPtr ()
	Get the raw AST pointer.

Static Public Member Functions
static std::shared_ptr< Object >	fromString (std::string const &str)
	Construct an Object from a string, using astFromString.
template<typename Class >
static std::shared_ptr< Class >	fromAstObject (AstObject *rawObj, bool copy)
	Given a bare AST object pointer return a shared pointer to an ast::Object of the correct type.

Protected Member Functions
	Mapping (AstMapping *rawMap)
	Construct a mapping from a pointer to a raw AST subclass of AstMapping.
virtual std::shared_ptr< Object >	copyPolymorphic () const override
	Return a deep copy of this object.
template<typename Class >
std::shared_ptr< Class >	decompose (int i, bool copy) const
	Return a deep copy of one of the two component mappings.
template<typename T , typename AstT >
std::shared_ptr< T >	copyImpl () const
	Implementation of deep copy.
bool	getB (std::string const &attrib) const
	Get the value of an attribute as a bool.
std::string const	getC (std::string const &attrib) const
	Get the value of an attribute as a string.
double	getD (std::string const &attrib) const
	Get the value of an attribute as a double.
float	getF (std::string const &attrib) const
	Get the value of an attribute as a float.
int	getI (std::string const &attrib) const
	Get the value of an attribute as an int.
long int	getL (std::string const &attrib) const
	Get the value of an attribute as a long int.
void	set (std::string const &setting)
	Assign a set of attribute values, over-riding any previous values.
void	setB (std::string const &attrib, bool value)
	Set the value of an attribute as a bool.
void	setC (std::string const &attrib, std::string const &value)
	Set the value of an attribute as a string.
void	setD (std::string const &attrib, double value)
	Set the value of an attribute as a double.
void	setF (std::string const &attrib, float value)
	Set the value of an attribute as a float.
void	setI (std::string const &attrib, int value)
	Set the value of an attribute as an int.
void	setL (std::string const &attrib, long int value)
	Set the value of an attribute as a long int.

Static Protected Member Functions
template<typename ShimT , typename AstT >
static std::shared_ptr< ShimT >	makeShim (AstObject *p)
	Functor to make an astshim instance from a raw AST pointer of the corresponding type.

Friends
class	Object

Detailed Description

An abstract base class for objects which transform one set of coordinates to another.

Mapping is used to describe the relationship which exists between two different coordinate systems and to implement operations which make use of this (such as transforming coordinates and resampling grids of data).

Attributes

In addition to those attributes common to Object, Mapping also has the following attributes:

• Invert: Is the mapping inverted?
• IsLinear: Is the Mapping linear?
• IsSimple: Has the Mapping been simplified?
• NIn: Number of input coordinates for a Mapping
• NOut: Number of output coordinates for a Mapping
• Report: Report transformed coordinates to stdout?
• TranForward: Is the forward transformation defined?
• TranInverse: Is the inverse transformation defined?

Definition at line 59 of file Mapping.h.

Member Typedef Documentation

ObjectPtr

using ast::Object::ObjectPtr = std::unique_ptr<AstObject, Deleter>

inherited

unique pointer holding an AST raw pointer

Definition at line 59 of file Object.h.

Constructor & Destructor Documentation

~Mapping()

virtual ast::Mapping::~Mapping ( )

inlinevirtual

Definition at line 63 of file Mapping.h.

{}

Mapping() [1/3]

ast::Mapping::Mapping ( Mapping const & )

default

Copy constructor: make a deep copy.

Mapping() [2/3]

ast::Mapping::Mapping ( Mapping && )

default

Mapping() [3/3]

ast::Mapping::Mapping ( AstMapping * rawMap )

inlineexplicitprotected

Construct a mapping from a pointer to a raw AST subclass of AstMapping.

Definition at line 400 of file Mapping.h.

                                         : Object(reinterpret_cast<AstObject *>(rawMap)) {
        assertOK();
        if (!astIsAMapping(getRawPtr())) {
            std::ostringstream os;
            os << "this is a " << getClassName() << ", which is not a Mapping";
            throw std::invalid_argument(os.str());
        }
    }

Member Function Documentation

applyForward() [1/3]

Array2D ast::Mapping::applyForward ( ConstArray2D const & from ) const

inline

Perform a forward transformation on a 2-D array, returning the results as a new array.

Parameters

[in]

from

input coordinates, with dimensions (nPts, nIn)

Returns

the results as a new array with dimensions (nPts, nOut)

Definition at line 268 of file Mapping.h.

                                                         {
        Array2D to = ndarray::allocate(getNOut(), from.getSize<1>());
        _tran(from, true, to);
        return to;
    }

applyForward() [2/3]

void ast::Mapping::applyForward ( ConstArray2D const & from, Array2D const & to ) const

inline

Perform a forward transformation on 2-D array, putting the results into a pre-allocated 2-D array.

Parameters

[in]	from	input coordinates, with dimensions (nPts, nIn)
[out]	to	transformed coordinates, with dimensions (nPts, nOut)

Definition at line 260 of file Mapping.h.

{ _tran(from, true, to); }

applyForward() [3/3]

std::vector< double > ast::Mapping::applyForward ( std::vector< double > const & from ) const

inline

Perform a forward transformation on a vector, returning the results as a new vector.

Parameters

[in]

from

input coordinates as a vector, with axes adjacent, e.g. x0, y0, x1, y1...xn, yn

Returns

the results as a new vector

Definition at line 280 of file Mapping.h.

                                                                        {
        auto fromArr = arrayFromVector(from, getNIn());
        std::vector<double> to(fromArr.getSize<1>() * getNOut());
        auto toArr = arrayFromVector(to, getNOut());
        _tran(fromArr, true, toArr);
        return to;
    }

applyInverse() [1/3]

Array2D ast::Mapping::applyInverse ( ConstArray2D const & from ) const

inline

Perform an inverse transformation on a 2-D array, returning the results as a new 2-D array.

Parameters

[in]

from

output coordinates, with dimensions (nPts, nOut)

Returns

the results as a new array with dimensions (nPts, nIn)

Definition at line 302 of file Mapping.h.

                                                         {
        Array2D to = ndarray::allocate(getNIn(), from.getSize<1>());
        _tran(from, false, to);
        return to;
    }

applyInverse() [2/3]

void ast::Mapping::applyInverse ( ConstArray2D const & from, Array2D const & to ) const

inline

Perform an inverse transformation on a 2-D array, putting the results into a pre-allocated 2-D array.

Parameters

[in]	from	input coordinates, with dimensions (nPts, nOut)
[out]	to	transformed coordinates, with dimensions (nPts, nIn)

Definition at line 294 of file Mapping.h.

{ _tran(from, false, to); }

applyInverse() [3/3]

std::vector< double > ast::Mapping::applyInverse ( std::vector< double > const & from ) const

inline

Perform an inverse transformation on a vector, returning the results as a new vector.

Parameters

[in]

from

input coordinates as a vector, with axes adjacent, e.g. x0, y0, x1, y1...xn, yn

Returns

the results as a new vector

Definition at line 314 of file Mapping.h.

                                                                        {
        auto fromArr = arrayFromVector(from, getNOut());
        std::vector<double> to(fromArr.getSize<1>() * getNIn());
        auto toArr = arrayFromVector(to, getNIn());
        _tran(fromArr, false, toArr);
        return to;
    }

clear()

void ast::Object::clear ( std::string const & attrib )

inlineinherited

Clear the values of a specified set of attributes for an Object.

Clearing an attribute cancels any value that has previously been explicitly set for it, so that the standard default attribute value will subsequently be used instead. This also causes the astTest function to return the value zero for the attribute, indicating that no value has been set.

Definition at line 119 of file Object.h.

                                        {
        astClear(getRawPtr(), attrib.c_str());
        assertOK();
    }

copy()

std::shared_ptr< Mapping > ast::Mapping::copy ( ) const

inline

Return a deep copy of this object.

Definition at line 72 of file Mapping.h.

{ return std::static_pointer_cast<Mapping>(copyPolymorphic()); }

copyImpl()

template<typename T , typename AstT >

std::shared_ptr< T > ast::Object::copyImpl ( ) const

inlineprotectedinherited

Implementation of deep copy.

Should be called to implement copyPolymorphic by all derived classes.

Definition at line 320 of file Object.h.

                                      {
        auto *rawptr = reinterpret_cast<AstT *>(astCopy(getRawPtr()));
        auto retptr = std::shared_ptr<T>(new T(rawptr));
        assertOK();
        return retptr;
    }

copyPolymorphic()

virtual std::shared_ptr< Object > ast::Mapping::copyPolymorphic ( ) const

inlineoverrideprotectedvirtual

Return a deep copy of this object.

This is called by copy.

Each subclass must override this method. The standard implementation is:

return copyImpl<astshim_class, ast_class>();

for example Frame implements this as:

return copyImpl<Frame, AstFrame>();

Implements ast::Object.

Reimplemented in ast::ChebyMap, ast::CmpFrame, ast::CmpMap, ast::Frame, ast::FrameDict, ast::FrameSet, ast::LutMap, ast::MathMap, ast::MatrixMap, ast::NormMap, ast::ParallelMap, ast::PcdMap, ast::PermMap, ast::PolyMap, ast::RateMap, ast::SeriesMap, ast::ShiftMap, ast::SkyFrame, ast::SlaMap, ast::SpecFrame, ast::SphMap, ast::TimeFrame, ast::TimeMap, ast::TranMap, ast::UnitMap, ast::UnitNormMap, ast::WcsMap, ast::WinMap, and ast::ZoomMap.

Definition at line 410 of file Mapping.h.

                                                                   {
        return std::static_pointer_cast<Mapping>(copyImpl<Mapping, AstMapping>());
    }

decompose()

template<typename Class >

template std::shared_ptr< Mapping > ast::Mapping::decompose ( int i, bool copy ) const

protected

Return a deep copy of one of the two component mappings.

This is intended to be exposed by classes that need it (e.g. CmpMap, CmpFrame and TranMap) as operator[].

Template Parameters

Class

astshim class of returned object, typically Mapping or Frame.

Parameters

[in]	i	Index: 0 for the first mapping, 1 for the second
[in]	copy	If true make a deep copy, else a shallow copy

Exceptions

std::invalid_argument	if i is not 0 or 1.
std::runtime_error	if this mapping is not a compound mapping.

Definition at line 64 of file Mapping.cc.

                                                              {
    if ((i < 0) || (i > 1)) {
        std::ostringstream os;
        os << "i =" << i << "; must be 0 or 1";
        throw std::invalid_argument(os.str());
    }
    // Report pre-existing problems now so our later test for "not a compound object" is accurate
    assertOK();
 
    AstMapping *rawMap1;
    AstMapping *rawMap2;
    int series, invert1, invert2;
    astDecompose(getRawPtr(), &rawMap1, &rawMap2, &series, &invert1, &invert2);
    assertOK();
 
    if (!rawMap2) {
        // Not a compound object; free rawMap1 (rawMap2 is null, so no need to free it) and throw an exception
        astAnnul(reinterpret_cast<AstObject *>(rawMap1));
        std::ostringstream os;
        os << "This " << getClassName() << " is not a compound object";
        throw std::runtime_error(os.str());
    }
 
    // Make a deep copy of the returned object and free the shallow copies
    AstMapping *retRawMap;
    int invert;
    if (i == 0) {
        retRawMap = reinterpret_cast<AstMapping *>(astCopy(reinterpret_cast<AstObject *>(rawMap1)));
        invert = invert1;
    } else {
        retRawMap = reinterpret_cast<AstMapping *>(astCopy(reinterpret_cast<AstObject *>(rawMap2)));
        invert = invert2;
    }
    astAnnul(reinterpret_cast<AstObject *>(rawMap1));
    astAnnul(reinterpret_cast<AstObject *>(rawMap2));
    assertOK();
 
    // If the mapping's internal invert flag does not match the value used when the CmpMap was made
    // then invert the mapping. Note that it is not possible to create such objects in astshim
    // but it is possible to read in objects created by other software.
    if (invert != astGetI(retRawMap, "Invert")) {
        astInvert(retRawMap);
        assertOK();
    }
 
    return Object::fromAstObject<Class>(reinterpret_cast<AstObject *>(retRawMap), copy);
}

fromAstObject()

template<typename Class >

template std::shared_ptr< Object > ast::Object::fromAstObject< Object > ( AstObject * rawObj, bool copy )

staticinherited

Given a bare AST object pointer return a shared pointer to an ast::Object of the correct type.

The returned object takes ownership of the pointer. This is almost always what you want, for instance astDecompose returns shallow copies of the internal pointers.

Template Parameters

Class

The class of the returned shared pointer. (The actual class will be the correct class of rawPtr.)

Parameters

[in]	rawObj	A bare AST object pointer
[in]	copy	If True then make a deep copy of the pointer (and free the original)

Definition at line 138 of file Object.cc.

                                                                       {
    AstObject *rawObjCopy = rawObj;
    if (copy) {
        rawObjCopy = reinterpret_cast<AstObject *>(astCopy(rawObj));
        astAnnul(rawObj);
    }
    assertOK(rawObjCopy);
 
    // Make the appropriate ast shim object and dynamically cast to the desired output type
    auto retObjectBeforeCast = Object::_basicFromAstObject(rawObjCopy);
    auto retObject = std::dynamic_pointer_cast<Class>(retObjectBeforeCast);
    if (!retObject) {
        std::ostringstream os;
        os << "The component is of type " << retObject->getClassName()
           << ", which could not be cast to the desired type " << typeid(Class).name();
        throw std::runtime_error(os.str());
    }
    return retObject;
}

fromString()

static std::shared_ptr< Object > ast::Object::fromString ( std::string const & str )

inlinestaticinherited

Construct an Object from a string, using astFromString.

Definition at line 88 of file Object.h.

                                                                  {
        auto *rawPtr = reinterpret_cast<AstObject *>(astFromString(str.c_str()));
        assertOK(rawPtr);
        return Object::_basicFromAstObject(rawPtr);
    }

getB()

bool ast::Object::getB ( std::string const & attrib ) const

inlineprotectedinherited

Get the value of an attribute as a bool.

If possible, the attribute value is converted to the type you request.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 348 of file Object.h.

                                             {
        bool val = astGetI(getRawPtr(), attrib.c_str());
        assertOK();
        return val;
    }

getC()

std::string const ast::Object::getC ( std::string const & attrib ) const

inlineprotectedinherited

Get the value of an attribute as a string.

If possible, the attribute value is converted to the type you request.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 361 of file Object.h.

                                                        {
        char const *rawval = astGetC(getRawPtr(), attrib.c_str());
        assertOK();
        return std::string(rawval);
    }

getClassName()

std::string ast::Object::getClassName ( ) const

inlineinherited

Get Class: the name of the class (e.g.

ZoomMap)

Note: if AST returns "CmpMap" then the name will be changed to "SeriesMap" or "ParallelMap", as appropriate.

Definition at line 139 of file Object.h.

{ return detail::getClassName(getRawPtr()); }

getD()

double ast::Object::getD ( std::string const & attrib ) const

inlineprotectedinherited

Get the value of an attribute as a double.

If possible, the attribute value is converted to the type you request.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 374 of file Object.h.

                                               {
        double val = astGetD(getRawPtr(), attrib.c_str());
        assertOK();
        return val;
    }

getF()

float ast::Object::getF ( std::string const & attrib ) const

inlineprotectedinherited

Get the value of an attribute as a float.

If possible, the attribute value is converted to the type you request.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 387 of file Object.h.

                                              {
        float val = astGetF(getRawPtr(), attrib.c_str());
        assertOK();
        return val;
    }

getI()

int ast::Object::getI ( std::string const & attrib ) const

protectedinherited

Get the value of an attribute as an int.

If possible, the attribute value is converted to the type you request.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 178 of file Object.cc.

                                              {
    int val = astGetI(getRawPtr(), attrib.c_str());
    assertOK();
    return val;
}

getID()

std::string ast::Object::getID ( ) const

inlineinherited

Get ID: object identification string that is not copied.

Definition at line 142 of file Object.h.

{ return getC("ID"); }

getIdent()

std::string ast::Object::getIdent ( ) const

inlineinherited

Get Ident: object identification string that is copied.

Definition at line 145 of file Object.h.

{ return getC("Ident"); }

getIsLinear()

bool ast::Mapping::getIsLinear ( ) const

inline

Get IsLinear: is the Mapping linear?

Definition at line 100 of file Mapping.h.

{ return getB("IsLinear"); }

getIsSimple()

bool ast::Mapping::getIsSimple ( ) const

inline

Get IsSimple: has the mapping been simplified?

Definition at line 87 of file Mapping.h.

{ return getI("IsSimple"); }

getL()

long int ast::Object::getL ( std::string const & attrib ) const

inlineprotectedinherited

Get the value of an attribute as a long int.

If possible, the attribute value is converted to the type you request.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 409 of file Object.h.

                                                 {
        long int val = astGetL(getRawPtr(), attrib.c_str());
        assertOK();
        return val;
    }

getNIn()

int ast::Mapping::getNIn ( ) const

inline

Get NIn: the number of input axes.

Definition at line 77 of file Mapping.h.

{ return getI("NIn"); }

getNObject()

int ast::Object::getNObject ( ) const

inlineinherited

Get NObject: number of AST objects in existence of the same type as the underlying AST class.

Warning

Intended only for debugging astshim.

Definition at line 153 of file Object.h.

{ return getI("NObject"); }

getNOut()

int ast::Mapping::getNOut ( ) const

inline

Get NOut: the number of output axes.

Definition at line 82 of file Mapping.h.

{ return getI("NOut"); }

getObjSize()

int ast::Object::getObjSize ( ) const

inlineinherited

Get ObjSize: the in-memory size of the AST object in bytes.

Definition at line 156 of file Object.h.

{ return getI("ObjSize"); }

getRawPtr() [1/2]

AstObject * ast::Object::getRawPtr ( )

inlineinherited

Get the raw AST pointer.

Intended for internal use only, but cannot be made protected without endless "friend class" declarations.

Definition at line 294 of file Object.h.

{ return &*_objPtr; };

getRawPtr() [2/2]

AstObject const * ast::Object::getRawPtr ( ) const

inlineinherited

Get the raw AST pointer.

Intended for internal use only, but cannot be made protected without endless "friend class" declarations.

Definition at line 292 of file Object.h.

{ return &*_objPtr; };

getRefCount()

int ast::Object::getRefCount ( ) const

inlineinherited

Get RefCount: number of active pointers to the underlying AST object.

Warning

Intended only for debugging astshim.

Definition at line 163 of file Object.h.

{ return getI("RefCount"); }

getReport()

bool ast::Mapping::getReport ( ) const

inline

Get Report: report transformed coordinates to stdout?

Definition at line 105 of file Mapping.h.

{ return getB("Report"); }

getUseDefs()

bool ast::Object::getUseDefs ( ) const

inlineinherited

Get UseDefs: allow use of default values for Object attributes?

Definition at line 166 of file Object.h.

{ return getB("UseDefs"); }

hasAttribute()

bool ast::Object::hasAttribute ( std::string const & attrib ) const

inlineinherited

Does this object have an attribute with the specified name?

Definition at line 127 of file Object.h.

                                                     {
        bool ret = astHasAttribute(getRawPtr(), attrib.c_str());
        assertOK();
        return ret;
    }

hasForward()

bool ast::Mapping::hasForward ( ) const

inline

Is the forward transform available?

Note

This gets the TranForward attribute, but is named hasForward instead of getTranForward for clarity, since it does not return a transform.

Definition at line 114 of file Mapping.h.

{ return getB("TranForward"); }

hasInverse()

bool ast::Mapping::hasInverse ( ) const

inline

Is the inverse transform available?

Note

This gets the TranInverse attribute, but is named hasInverse instead of getTranInverse for clarity, since it does not return a transform.

Definition at line 123 of file Mapping.h.

{ return getB("TranInverse"); }

inverted()

std::shared_ptr< Mapping > ast::Mapping::inverted

(

)

const

Get an inverse mapping.

An inverse mapping is a deep copy of a mapping whose Invert attribute has been toggled, as indicated by isInverted. This swaps the meaning of "input" and "output", and of "forward" and "inverse". Thus it swaps the behavior of applyForward and applyInverse, getNIn and getNOut, hasForward and hasInverse and so on.

Note that the inverse mapping contains exactly the same model coefficients as the original, but they are used by applyInverse instead of applyForward. Thus for example if a ZoomMap has a zoom factor of 4.0 then its inverse also reports a zoom factor of 4.0 (despite behaving like an uninverted ZoomMap with zoom factor of 0.25).

Definition at line 41 of file Mapping.cc.

                                               {
    auto rawCopy = reinterpret_cast<AstMapping *>(astCopy(getRawPtr()));
    astInvert(rawCopy);
    assertOK(reinterpret_cast<AstObject *>(rawCopy));
    // use false because the pointer has already been copied
    return Object::fromAstObject<Mapping>(reinterpret_cast<AstObject *>(rawCopy), false);
}

isInverted()

bool ast::Mapping::isInverted ( ) const

inline

Is this an inverted mapping?

Note: this gets the Invert attribute. This method is not called getInvert because that sounds like it might return the inverse.

Definition at line 95 of file Mapping.h.

{ return getB("Invert"); }

linearApprox()

Array2D ast::Mapping::linearApprox	(	PointD const &	lbnd,
		PointD const &	ubnd,
		double	tol ) const

Compute a linear approximation to the forward transformation.

Parameters

[in]	lbnd	Input point defining the lower bounds of the box over which the linear approximation is computed.
[in]	ubnd	Input point defining the upper bounds of the box over which the linear approximation is computed.
[in]	tol	The maximum permitted deviation from linearity, expressed as apositive Cartesian displacement in the output coordinate space. If a linear fit to the forward transformation of the Mapping deviates from the true transformation by more than this amount at any point which is tested, then raise an exception.

Returns

The co-efficients of the linear approximation to the specified transformation, as an 1 + nIn x nOut array. The first index is [constant, gradiant for input 1, gradiant for input 2...] and the second index is [output 1, output 2, ...]. For example, if the Mapping has 2 inputs and 3 outputs then the coefficients are:

X_out = fit[0, 0] + fit[1, 0] X_in + fit[2, 0] Y_in
Y_out = fit[0, 1] + fit[1, 1] X_in + fit[2, 1] Y_in
Z_out = fit[0, 2] + fit[1, 2] X_in + fit[2, 2] Y_in

Exceptions

std::runtime_error

if the forward transformation cannot be modeled to within the specified tol.

Definition at line 49 of file Mapping.cc.

                                                                                      {
    int const nIn = getNIn();
    int const nOut = getNOut();
    detail::assertEqual(lbnd.size(), "lbnd.size", static_cast<std::size_t>(nIn), "nIn");
    detail::assertEqual(ubnd.size(), "ubnd.size", static_cast<std::size_t>(nIn), "nIn");
    Array2D fit = ndarray::allocate(ndarray::makeVector(1 + nIn, nOut));
    int isOK = astLinearApprox(getRawPtr(), lbnd.data(), ubnd.data(), tol, fit.getData());
    assertOK();
    if (!isOK) {
        throw std::runtime_error("Mapping not sufficiently linear");
    }
    return fit;
}

lock()

void ast::Object::lock ( bool wait )

inlineinherited

Lock this object for exclusive use by the calling thread.

The thread-safe public interface to AST is designed so that an error is reported if any thread attempts to use an Object that it has not previously locked for its own exclusive use using this function. When an Object is created, it is initially locked by the thread that creates it, so newly created objects do not need to be explicitly locked. However, if an Object pointer is passed to another thread, the original thread must first unlock it (using astUnlock) and the new thread must then lock it (using astLock) before the new thread can use the Object.

Parameters

[in]

wait

If the Object is curently locked by another thread then this function will either report an error or block. If a non-zero value is supplied for "wait", the calling thread waits until the object is available for it to use. Otherwise, an error is reported and the function returns immediately without locking the Object.

Notes

• The Locked object will belong to the current AST context.
• This function returns without action if the Object is already locked by the calling thread.
• If simultaneous use of the same object is required by two or more threads, Object::copy should be used to to produce a deep copy of the Object for each thread. Each copy should then be unlocked by the parent thread (i.e. the thread that created the copy), and then locked by the child thread (i.e. the thread that wants to use the copy).
• This function returns without action if the AST library has been built without POSIX thread support (i.e. the "-with-pthreads" option was not specified when running the "configure" script).

Definition at line 202 of file Object.h.

                         {
        astLock(getRawPtr(), static_cast<int>(wait));
        assertOK();
    }

makeShim()

template<typename ShimT , typename AstT >

static std::shared_ptr< ShimT > ast::Object::makeShim ( AstObject * p )

inlinestaticprotectedinherited

Functor to make an astshim instance from a raw AST pointer of the corresponding type.

Template Parameters

ShimT	Output astshim class
AstT	Output AST class

Definition at line 310 of file Object.h.

                                                       {
        return std::shared_ptr<ShimT>(new ShimT(reinterpret_cast<AstT *>(p)));
    }

operator!=()

bool ast::Object::operator!= ( Object const & rhs ) const

inlineinherited

Return True if this and rhs are not equal.

See operator== for details

Definition at line 82 of file Object.h.

                                             {
        return !(*this == rhs); };

operator=() [1/2]

Mapping & ast::Mapping::operator= ( Mapping && )

default

operator=() [2/2]

Mapping & ast::Mapping::operator= ( Mapping const & )

delete

operator==()

bool ast::Object::operator== ( Object const & rhs ) const

inherited

Return True if this and rhs are the equal.

For two objects be equal, they both must have the same attributes and all contained objects must be equal.

Definition at line 85 of file Object.cc.

                                               {
    auto thisStr = this->show(false);
    auto rhsStr = rhs.show(false);
    return rhsStr == thisStr;
}

rate()

double ast::Mapping::rate ( PointD const & at, int ax1, int ax2 ) const

inline

Evaluate the rate of change of the Mapping with respect to a specified input, at a specified position.

The result is estimated by interpolating the function using a fourth order polynomial in the neighbourhood of the specified position. The size of the neighbourhood used is chosen to minimise the RMS residual per unit length between the interpolating polynomial and the supplied Mapping function. This method produces good accuracy but can involve evaluating the Mapping 100 or more times.

Parameters

[in]	at	The input position at which the rate of change is to be evaluated.
[in]	ax1	The index of the output for which the rate of change is to be found (1 for first output).
[in]	ax2	The index of the input which is to be varied in order to find the rate of change (1 for the first input).

Returns

The rate of change of Mapping output ax1 with respect to input ax2, evaluated at at, or nan if the value cannot be calculated.

Definition at line 215 of file Mapping.h.

                                                          {
        detail::assertEqual(at.size(), "at.size", static_cast<std::size_t>(getNIn()), "nIn");
        double result = astRate(getRawPtr(), const_cast<double *>(at.data()), ax1, ax2);
        assertOK();
        return result;
    }

same()

bool ast::Object::same ( Object const & other ) const

inlineinherited

Does this contain the same AST object as another?

This is a test of identity, not of equality.

Definition at line 212 of file Object.h.

{ return astSame(getRawPtr(), other.getRawPtr()); }

set()

void ast::Object::set ( std::string const & setting )

inlineprotectedinherited

Assign a set of attribute values, over-riding any previous values.

The attributes and their new values are specified via a character string, which should contain a comma-separated list of the form: "attribute_1 = value_1, attribute_2 = value_2, ... " where "attribute_n" specifies an attribute name, and the value to the right of each " =" sign should be a suitable textual representation of the value to be assigned. This value will be interpreted according to the attribute's data type.

Notes

• Attribute names are not case sensitive and may be surrounded by white space
• Attribute names are not case sensitive and may be surrounded by white space.
• White space may also surround attribute values, where it will generally be ignored (except for string-valued attributes where it is significant and forms part of the value to be assigned).
• To include a literal comma or percent sign in the value assigned to an attribute, the whole attribute value should be enclosed in quotation markes.

Exceptions

std::runtime_error

if the attribute is read-only

Definition at line 436 of file Object.h.

                                       {
        astSet(getRawPtr(), "%s", setting.c_str());
        assertOK();
    }

setB()

void ast::Object::setB ( std::string const & attrib, bool value )

inlineprotectedinherited

Set the value of an attribute as a bool.

If possible, the type you provide is converted to the actual type of the attribute.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 448 of file Object.h.

                                                   {
        astSetI(getRawPtr(), attrib.c_str(), value);
        assertOK();
    }

setC()

void ast::Object::setC ( std::string const & attrib, std::string const & value )

inlineprotectedinherited

Set the value of an attribute as a string.

If possible, the type you provide is converted to the actual type of the attribute.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 460 of file Object.h.

                                                               {
        astSetC(getRawPtr(), attrib.c_str(), value.c_str());
        assertOK();
    }

setD()

void ast::Object::setD ( std::string const & attrib, double value )

inlineprotectedinherited

Set the value of an attribute as a double.

If possible, the type you provide is converted to the actual type of the attribute.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 472 of file Object.h.

                                                     {
        astSetD(getRawPtr(), attrib.c_str(), value);
        assertOK();
    }

setF()

void ast::Object::setF ( std::string const & attrib, float value )

inlineprotectedinherited

Set the value of an attribute as a float.

If possible, the type you provide is converted to the actual type of the attribute.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 484 of file Object.h.

                                                    {
        astSetF(getRawPtr(), attrib.c_str(), value);
        assertOK();
    }

setI()

void ast::Object::setI ( std::string const & attrib, int value )

inlineprotectedinherited

Set the value of an attribute as an int.

If possible, the type you provide is converted to the actual type of the attribute.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 496 of file Object.h.

                                                  {
        astSetI(getRawPtr(), attrib.c_str(), value);
        assertOK();
    }

setID()

void ast::Object::setID ( std::string const & id )

inlineinherited

Set ID: object identification string that is not copied.

Definition at line 215 of file Object.h.

{ setC("ID", id); }

setIdent()

void ast::Object::setIdent ( std::string const & ident )

inlineinherited

Set Ident: object identification string that is copied.

Definition at line 218 of file Object.h.

{ setC("Ident", ident); }

setL()

void ast::Object::setL ( std::string const & attrib, long int value )

inlineprotectedinherited

Set the value of an attribute as a long int.

If possible, the type you provide is converted to the actual type of the attribute.

Exceptions

std::runtime_error

if the attribute does not exist or the value cannot be converted

Definition at line 508 of file Object.h.

                                                       {
        astSetL(getRawPtr(), attrib.c_str(), value);
        assertOK();
    }

setReport()

void ast::Mapping::setReport ( bool report )

inline

Set Report: report transformed coordinates to stdout?

Definition at line 225 of file Mapping.h.

{ setB("Report", report); }

setUseDefs()

void ast::Object::setUseDefs ( bool usedefs )

inlineinherited

Set UseDefs: allow use of default values for Object attributes?

Definition at line 221 of file Object.h.

{ setB("UseDefs", usedefs); }

show() [1/2]

std::string ast::Object::show ( bool showComments = true ) const

inherited

Return a textual description the object as a string.

Parameters

[in]

showComments

Show comments?

Definition at line 165 of file Object.cc.

                                              {
    std::ostringstream os;
    show(os, showComments);
    return os.str();
}

show() [2/2]

void ast::Object::show ( std::ostream & os, bool showComments = true ) const

inherited

Print a textual description the object to an ostream.

Parameters

[in,out]	os	The stream to which to write the string representation.
[in]	showComments	Show comments?

Definition at line 158 of file Object.cc.

                                                         {
    Stream stream(nullptr, &os);
    Channel ch(stream, showComments ? "" : "Comment=0");
    ch.write(*this);
    assertOK();
}

simplified()

std::shared_ptr< Mapping > ast::Mapping::simplified ( ) const

inline

Return a simplied version of the mapping (which may be a compound Mapping such as a CmpMap).

Simplification eliminates redundant computational steps and merges separate steps which can be performed more efficiently in a single operation. As a simple example, a Mapping which multiplied coordinates by 5, and then multiplied the result by 10, could be simplified to a single step which multiplied by 50. Similarly, a Mapping which multiplied by 5, and then divided by 5, could be reduced to a simple copying operation.

This function should typically be applied to Mappings which have undergone substantial processing or have been formed by merging other Mappings. It is of potential benefit, for example, in reducing execution time if applied before using a Mapping to transform a large number of coordinates.

Note

If the supplied Mapping is a FrameSet, the returned Mapping will be a deep copy of the supplied FrameSet in which all the inter-Frame Mappings have been simplified. Mappings that have a set value for their ref Object_Ident "Ident" attribute are unchanged by simplification. This is so that their individual identity is preserved. This restriction does not apply to the simplification of Frames. The returned mapping is always independent of the original (a deep copy), unlike astSimplify.

Definition at line 248 of file Mapping.h.

                                              {
        AstObject *rawSimpMap = reinterpret_cast<AstObject *>(astSimplify(getRawPtr()));
        assertOK(rawSimpMap);
        return Object::fromAstObject<Mapping>(rawSimpMap, true);
    }

test()

bool ast::Object::test ( std::string const & attrib ) const

inlineinherited

Has this attribute been explicitly set (and not subsequently cleared)?

Warning

Unlike the underlying astTest function, throws an exception if an error results

Notes

• Attribute names are not case sensitive and may be surrounded by white space.
• As you might expect, the returned value for a read-only attribute is always false.

Exceptions

std::runtime_error

if an error results.

Definition at line 250 of file Object.h.

                                             {
        bool res = astTest(getRawPtr(), attrib.c_str());
        assertOK();
        return res;
    }

then()

SeriesMap ast::Mapping::then

(

Mapping const &

next

)

const

Return a series compound mapping this(first(input)) containing shallow copies of the original.

Parameters

[in]

next

the mapping whose input is the output of this mapping

Exceptions

std::invalid_argument

if the number of input axes of next does not match the number of output axes of this mapping.

Warning

The contained mappings are shallow copies (just like AST); if you want deep copies then make them manually.

Definition at line 37 of file Mapping.cc.

{ return SeriesMap(*this, next); }

tranGridForward() [1/2]

void ast::Mapping::tranGridForward ( PointI const & lbnd, PointI const & ubnd, double tol, int maxpix, Array2D const & to ) const

inline

Transform a grid of points in the forward direction.

Parameters

[in]	lbnd	The coordinates of the centre of the first pixel in the input grid along each dimension, size = nIn
[in]	ubnd	The coordinates of the centre of the last pixel in the input grid along each dimension, size = nIn
[in]	tol	The maximum tolerable geometrical distortion which may be introduced as a result of approximating non-linear Mappings by a set of piece-wise linear transformations. This should be expressed as a displacement within the output coordinate system of the Mapping.

If piece-wise linear approximation is not required, a value of zero may be given. This will ensure that the Mapping is used without any approximation, but may increase execution time.

If the value is too high, discontinuities between the linear approximations used in adjacent panel will be higher. If this is a problem, reduce the tolerance value used.

Parameters

[in]	maxpix	A value which specifies an initial scale size (in input grid points) for the adaptive algorithm which approximates non-linear Mappings with piece-wise linear transformations. Normally, this should be a large value (larger than any dimension of the region of the input grid being used). In this case, a first attempt to approximate the Mapping by a linear transformation will be made over the entire input region. If a smaller value is used, the input region will first be divided into sub-regions whose size does not exceed " maxpix" grid points in any dimension. Only at this point will attempts at approximation commence. This value may occasionally be useful in preventing false convergence of the adaptive algorithm in cases where the Mapping appears approximately linear on large scales, but has irregularities (e.g. holes) on smaller scales. A value of, say, 50 to 100 grid points can also be employed as a safeguard in general-purpose software, since the effect on performance is minimal. If too small a value is given, it will have the effect of inhibiting linear approximation altogether (equivalent to setting " tol" to zero). Although this may degrade performance, accurate results will still be obtained.
[in]	to	Computed points, with dimensions (nPts, nOut), where nPts the desired number of points

Definition at line 358 of file Mapping.h.

                                                  {
        _tranGrid(lbnd, ubnd, tol, maxpix, true, to);
    }

tranGridForward() [2/2]

Array2D ast::Mapping::tranGridForward ( PointI const & lbnd, PointI const & ubnd, double tol, int maxpix, int nPts ) const

inline

Transform a grid of points in the inverse direction, returning the results as a new Array2D.

See the overload of tranGridForward that outputs the data as the last argument for more information

Definition at line 369 of file Mapping.h.

                                                                                                            {
        Array2D to = ndarray::allocate(nPts, getNOut());
        _tranGrid(lbnd, ubnd, tol, maxpix, true, to);
        return to;
    }

tranGridInverse() [1/2]

void ast::Mapping::tranGridInverse ( PointI const & lbnd, PointI const & ubnd, double tol, int maxpix, Array2D const & to ) const

inline

Transform a grid of points in the inverse direction.

See tranGridForward for the arguments, swapping nIn and nOut

Definition at line 380 of file Mapping.h.

                                                  {
        _tranGrid(lbnd, ubnd, tol, maxpix, false, to);
    }

tranGridInverse() [2/2]

Array2D ast::Mapping::tranGridInverse ( PointI const & lbnd, PointI const & ubnd, double tol, int maxpix, int nPts ) const

inline

Transform a grid of points in the inverse direction.

See tranGridForward for the arguments, swapping nIn and nOut

Definition at line 390 of file Mapping.h.

                                                                                                            {
        Array2D to = ndarray::allocate(nPts, getNIn());
        _tranGrid(lbnd, ubnd, tol, maxpix, false, to);
        return to;
    }

under()

ParallelMap ast::Mapping::under

(

Mapping const &

next

)

const

Return a parallel compound mapping containing shallow copies of the original.

The resulting mapping has getNIn() + next.getNIn() inputs and getNOut() + next.getNOut() outputs. The first getNIn() axes of input are transformed by this mapping, producing the first getNOut() axes of output. The remaining axes of input are processed by next, resulting in the remaining axes of output.

The name comes the way vectors are sometimes shown for matrix multiplication: vertically, with the first axis at the bottom and the last axis at the top.

Parameters

[in]

next

the mapping that processes the final next.getNin() axes of input to produce the final next.getNout() axes of output.

Warning

The contained mappings are shallow copies (just like AST); if you want deep copies then make them manually.

Definition at line 39 of file Mapping.cc.

{ return ParallelMap(*this, next); }

unlock()

void ast::Object::unlock ( bool report = false )

inlineinherited

Unlock this object previously locked using lock, so that other threads can use this object.

See lock for further details.

Parameters

[in]

report

If true, an error will be reported if the supplied Object, or any Object contained within the supplied Object, is not currently locked by the running thread. If false, such Objects will be left unchanged, and no error will be reported.

Notes

• This function attempts to execute even if AST's global error status is set, but no further error report will be made if it subsequently fails under these circumstances.
• All unlocked Objects are excluded from AST context handling until they are re-locked using astLock.
• This function returns without action if the Object is not currently locked by any thread. If it is locked by the running thread, it is unlocked. If it is locked by another thread, an error will be reported if "error" is non-zero.
• This function returns without action if the AST library has been built without POSIX thread support (i.e. the "-with-pthreads" option was not specified when running the "configure" script).

Definition at line 280 of file Object.h.

                                     {
        astUnlock(getRawPtr(), static_cast<int>(report));
        assertOK();
    }

Friends And Related Symbol Documentation

Object

friend class Object

friend

Definition at line 60 of file Mapping.h.

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-9.0.0/Linux64/astshim/g3156d2b45e+41e33cbcdc/include/astshim/Mapping.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-9.0.0/Linux64/astshim/g3156d2b45e+41e33cbcdc/src/Mapping.cc