PolyMap is a Mapping which performs a general polynomial transformation. More...

#include <PolyMap.h>

Inheritance diagram for ast::PolyMap:

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

Public Member Functions
	PolyMap (ConstArray2D const &coeff_f, ConstArray2D const &coeff_i, std::string const &options="IterInverse=0")
	Construct a PolyMap with specified forward and/or inverse transforms.
	PolyMap (ConstArray2D const &coeff_f, int nout, std::string const &options="IterInverse=0")
	Construct a PolyMap with only the forward transform specified.
virtual	~PolyMap ()
	PolyMap (PolyMap const &)=default
	Copy constructor: make a deep copy.
	PolyMap (PolyMap &&)=default
PolyMap &	operator= (PolyMap const &)=delete
PolyMap &	operator= (PolyMap &&)=default
std::shared_ptr< PolyMap >	copy () const
	Return a deep copy of this object.
bool	getIterInverse () const
	Get IterInverse: does this provide an iterative inverse transformation?
int	getNIterInverse () const
	Get NIterInverse: maximum number of iterations for iterative inverse.
double	getTolInverse () const
	Get TolInverse: target relative error for iterative inverse.
PolyMap	polyTran (bool forward, double acc, double maxacc, int maxorder, std::vector< double > const &lbnd, std::vector< double > const &ubnd) const
	This function creates a new PolyMap which is a copy of this one, in which a specified transformation (forward or inverse) has been replaced by a new polynomial transformation.
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
virtual std::shared_ptr< Object >	copyPolymorphic () const override
	Return a deep copy of this object.
	PolyMap (AstPolyMap *map)
	Construct a PolyMap from an raw AST pointer.
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

PolyMap is a Mapping which performs a general polynomial transformation.

Each output coordinate is a polynomial function of all the input coordinates. The coefficients are specified separately for each output coordinate. The forward and inverse transformations are defined independantly by separate sets of coefficients. If no inverse transformation is supplied, an iterative method can be used to evaluate the inverse based only on the forward transformation.

Attributes

All those of Mapping plus:

IterInverse: provide an iterative inverse transformation?
NIterInverse: maximum number of iterations for iterative inverse.
TolInverse: target relative error for iterative inverse.

Definition at line 49 of file PolyMap.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

◆ PolyMap() [1/5]

ast::PolyMap::PolyMap	(	ConstArray2D const &	coeff_f,
		ConstArray2D const &	coeff_i,
		std::string const &	options = "IterInverse=0" )

inlineexplicit

Construct a PolyMap with specified forward and/or inverse transforms.

The two sets of coefficients are independent of each other: the inverse transform need not undo the forward transform.

Parameters

[in]	coeff_f	A matrix of coefficients describing the forward transformation. If coeff_f is empty then no forward transformation is provided.
[in]	coeff_i	A matrix of coefficients describing the inverse transformation. If coeff_i is empty then no inverse transformation is provided, unless you specify suitable options to request an iterative inverse; see the other constructor for details.
[in]	options	Comma-separated list of attribute assignments.

Exceptions

std::invalid_argument if neither transform is specified (coeff_f and coeff_i are both empty)

Coefficient Matrices

The coefficients describing a forward transformation are specified as 2-dimensional ndarray, with one row per coefficient. Each row contains the following consecutive (2 + nin) values:

The first element is the coefficient value.
The next element is the integer index of the PolyMap output which uses the coefficient within its defining polynomial (the first output has index 1).
The remaining elements give the integer power to use with each corresponding input coordinate value, or 0 to ignore that input coordinate. Powers must not be negative and floating point values are rounded to the nearest integer.

For example, suppose you want to make a PolyMap with 3 inputs and 2 outputs. Then each row of coeff_f must have 5 = 2 + nin elements. A row with values (1.2, 2, 6, 3, 0) describes a coefficient that increments output 2 as follows:

`out2 += 1.2 * in1^6 * in2^3 * in3^0`

and a row with values (-1.5, 1, 0, 0, 0) describes a coefficient that increments output 2 with a constant value of -1.5 (since all powers are 0):

`out1 += -1.5 * in1^0 * in2^0 * in3^0`

The final value of each output coordinate is the sum of all values specified by coefficients which increment that output coordinate, or 0 if there are no such coefficients.

The coefficients describing the inverse transformation work the same way, of course, but each coefficient is described by (2 + nout) values.

Definition at line 99 of file PolyMap.h.

◆ PolyMap() [2/5]

ast::PolyMap::PolyMap	(	ConstArray2D const &	coeff_f,
		int	nout,
		std::string const &	options = "IterInverse=0" )

inlineexplicit

Construct a PolyMap with only the forward transform specified.

If the polynomial is invertible and you want an inverse you have two choices: either specify suitable options to request an iterative inverse, or call polyTran to fit an inverse. Both have advantages:

The iterative inverse should provide valid values even if multiple choices exist, and nan if no valid choice exists, whereas polyTran will raise an exception if a single-valued inverse cannot be found over the specified range.
The iterative inverse has no range restriction, whereas polyTran produces an inverse that is valid over a specified range.
The polyTran inverse is more efficient to compute.

Parameters

[in]	coeff_f	A (2 + nin) x ncoeff_f matrix of coefficients describing the forward transformation. If coeff_f is empty then no forward transformation is provided.
[in]	nout	Number of output coordinates.
[in]	options	Comma-separated list of attribute assignments. Useful attributes include: IterInverse, NIterInverse and TolInverse.

Exceptions

std::invalid_argument if the forward transform is not specified (coeff_f is empty)

Definition at line 126 of file PolyMap.h.

◆ ~PolyMap()

virtual ast::PolyMap::~PolyMap ( )

inlinevirtual

Definition at line 129 of file PolyMap.h.

◆ PolyMap() [3/5]

ast::PolyMap::PolyMap ( PolyMap const & )

default

Copy constructor: make a deep copy.

◆ PolyMap() [4/5]

ast::PolyMap::PolyMap ( PolyMap && )

default

◆ PolyMap() [5/5]

ast::PolyMap::PolyMap ( AstPolyMap * map )

protected

Construct a PolyMap from an raw AST pointer.

Definition at line 50 of file PolyMap.cc.

Member Function Documentation

◆ applyForward() [1/3]

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

inlineinherited

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.

◆ applyForward() [2/3]

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

inlineinherited

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.

◆ applyForward() [3/3]

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

inlineinherited

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.

◆ applyInverse() [1/3]

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

inlineinherited

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.

◆ applyInverse() [2/3]

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

inlineinherited

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.

◆ applyInverse() [3/3]

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

inlineinherited

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.

◆ 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.

◆ copy()

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

inline

Return a deep copy of this object.

Definition at line 138 of file PolyMap.h.

◆ 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.

◆ copyPolymorphic()

virtual std::shared_ptr< Object > ast::PolyMap::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>();

ast::Object::copyImpl

std::shared_ptr< T > copyImpl() const

Implementation of deep copy.

Definition Object.h:320

for example Frame implements this as:

return copyImpl<Frame, AstFrame>();

Reimplemented from ast::Mapping.

Definition at line 236 of file PolyMap.h.

◆ decompose()

template<typename Class>

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

protectedinherited

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.

◆ 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 140 of file Object.cc.

◆ fromString()

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.

◆ 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.

◆ 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.

◆ 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.

◆ 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.

◆ 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.

◆ 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 180 of file Object.cc.

◆ 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.

◆ getIdent()

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

inlineinherited

Get Ident: object identification string that is copied.

Definition at line 145 of file Object.h.

◆ getIsLinear()

bool ast::Mapping::getIsLinear ( ) const

inlineinherited

Get IsLinear: is the Mapping linear?

Definition at line 100 of file Mapping.h.

◆ getIsSimple()

bool ast::Mapping::getIsSimple ( ) const

inlineinherited

Get IsSimple: has the mapping been simplified?

Definition at line 87 of file Mapping.h.

◆ getIterInverse()

bool ast::PolyMap::getIterInverse ( ) const

inline

Get IterInverse: does this provide an iterative inverse transformation?

Definition at line 141 of file PolyMap.h.

◆ 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.

◆ getNIn()

int ast::Mapping::getNIn ( ) const

inlineinherited

Get NIn: the number of input axes.

Definition at line 77 of file Mapping.h.

◆ getNIterInverse()

int ast::PolyMap::getNIterInverse ( ) const

inline

Get NIterInverse: maximum number of iterations for iterative inverse.

Definition at line 144 of file PolyMap.h.

◆ 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.

◆ getNOut()

int ast::Mapping::getNOut ( ) const

inlineinherited

Get NOut: the number of output axes.

Definition at line 82 of file Mapping.h.

◆ 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.

◆ 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.

◆ 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.

◆ 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.

◆ getReport()

bool ast::Mapping::getReport ( ) const

inlineinherited

Get Report: report transformed coordinates to stdout?

Definition at line 105 of file Mapping.h.

◆ getTolInverse()

double ast::PolyMap::getTolInverse ( ) const

inline

Get TolInverse: target relative error for iterative inverse.

Definition at line 147 of file PolyMap.h.

◆ 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.

◆ 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.

◆ hasForward()

bool ast::Mapping::hasForward ( ) const

inlineinherited

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.

◆ hasInverse()

bool ast::Mapping::hasInverse ( ) const

inlineinherited

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.

◆ inverted()

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

inherited

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.

◆ isInverted()

bool ast::Mapping::isInverted ( ) const

inlineinherited

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.

◆ linearApprox()

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

inherited

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.

◆ 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.

◆ makeShim()

template<typename ShimT, typename AstT>

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.

◆ 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.

◆ operator=() [1/2]

PolyMap & ast::PolyMap::operator= ( PolyMap && )

default

◆ operator=() [2/2]

PolyMap & ast::PolyMap::operator= ( PolyMap 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 86 of file Object.cc.

◆ polyTran()

PolyMap ast::PolyMap::polyTran	(	bool	forward,
		double	acc,
		double	maxacc,
		int	maxorder,
		std::vector< double > const &	lbnd,
		std::vector< double > const &	ubnd ) const

This function creates a new PolyMap which is a copy of this one, in which a specified transformation (forward or inverse) has been replaced by a new polynomial transformation.

The coefficients of the new transformation are estimated by sampling the other transformation and performing a least squares polynomial fit in the opposite direction to the sampled positions and values.

IterInverse will be cleared in the returned mapping if the inverse was fit by polyTran.

This method can only be used on (1-input,1-output) or (2-input, 2-output) PolyMaps.

The transformation to create is specified by the forward parameter. In what follows "X" refers to the inputs of the PolyMap, and "Y" to the outputs of the PolyMap. The forward transformation transforms input values (X) into output values (Y), and the inverse transformation transforms output values (Y) into input values (X). Within a PolyMap, each transformation is represented by an independent set of polynomials, P_f or P_i: Y=P_f(X) for the forward transformation and X=P_i(Y) for the inverse transformation.

The forward parameter specifies the transformation to be replaced. If it is true, a new forward transformation is created by first finding the input values (X) using the inverse transformation (which must be available) at a regular grid of points (Y) covering a rectangular region of the PolyMap's output space. The coefficients of the required forward polynomial, Y=P_f(X), are chosen in order to minimise the sum of the squared residuals between the sampled values of Y and P_f(X).

If forward is false (probably the most likely case), a new inverse transformation is created by first finding the output values (Y) using the forward transformation (which must be available) at a regular grid of points (X) covering a rectangular region of the PolyMap's input space. The coefficients of the required inverse polynomial, X=P_i(Y), are chosen in order to minimise the sum of the squared residuals between the sampled values of X and P_i(Y).

This fitting process is performed repeatedly with increasing polynomial orders (starting with linear) until the target accuracy is achieved, or a specified maximum order is reached. If the target accuracy cannot be achieved even with this maximum-order polynomial, the best fitting maximum-order polynomial is returned so long as its accuracy is better than "maxacc". If it is not, an error is reported.

Parameters

[in]	forward	If true the forward transformation is replaced. Otherwise the inverse transformation is replaced.
[in]	acc	The target accuracy, expressed as a geodesic distance within the PolyMap's input space (if forward is false) or output space (if forward is true).
[in]	maxacc	The maximum allowed accuracy for an acceptable polynomial, expressed as a geodesic distance within the PolyMap's input space (if forward is false) or output space (if forward is true).
[in]	maxorder	The maximum allowed polynomial order. This is one more than the maximum power of either input axis. So for instance, a value of 3 refers to a quadratic polynomial. Note, cross terms with total powers greater than or equal to maxorder are not inlcuded in the fit. So the maximum number of terms in each of the fitted polynomials is maxorder*(maxorder + 1)/2.
[in]	lbnd	A vector holding the lower bounds of a rectangular region within the PolyMap's input space (if forward is false) or output space (if forward is true). The new polynomial will be evaluated over this rectangle. The length should equal getNIn() or getNOut(), depending on forward.
[in]	ubnd	A vector holding the upper bounds of a rectangular region within the PolyMap's input space (if forward is false) or output space (if forward is true). The new polynomial will be evaluated over this rectangle. The length should equal getNIn() or getNOut(), depending on forward.

Exceptions

std::invalid_argument	if the size of lbnd or ubnd does not match getNIn() (if forward false) or getNOut() (if forward true).
std::invalid_argument	if forward true and the inverse transform is iterative (even if this transform also has inverse coefficients, since the result is unlikely to match user expectations)
std::invalid_argument	if forward false and the forward transform is iterative (even if this transform also has forward coefficients, since the result is unlikely to match user expectations)

Definition at line 30 of file PolyMap.cc.

◆ rate()

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

inlineinherited

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.

◆ 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.

◆ 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.

◆ 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.

◆ 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.

◆ 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.

◆ 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.

◆ 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.

◆ 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.

◆ 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.

◆ 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.

◆ setReport()

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

inlineinherited

Set Report: report transformed coordinates to stdout?

Definition at line 225 of file Mapping.h.

◆ 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.

◆ 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 167 of file Object.cc.

◆ 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 160 of file Object.cc.

◆ simplified()

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

inlineinherited

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.

◆ 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.

◆ then()

SeriesMap ast::Mapping::then ( Mapping const & next ) const

inherited

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.

◆ tranGridForward() [1/2]

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

inlineinherited

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.

◆ tranGridForward() [2/2]

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

inlineinherited

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.

◆ tranGridInverse() [1/2]

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

inlineinherited

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.

◆ tranGridInverse() [2/2]

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

inlineinherited

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.

◆ under()

ParallelMap ast::Mapping::under ( Mapping const & next ) const

inherited

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.

◆ 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.

◆ Object

friend class Object

friend

Definition at line 50 of file PolyMap.h.

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

include/astshim/PolyMap.h
src/PolyMap.cc

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Friends

Detailed Description

Attributes

Member Typedef Documentation

◆ ObjectPtr

Constructor & Destructor Documentation

◆ PolyMap() [1/5]

◆ PolyMap() [2/5]

◆ ~PolyMap()

◆ PolyMap() [3/5]

◆ PolyMap() [4/5]

◆ PolyMap() [5/5]

Member Function Documentation

◆ applyForward() [1/3]

◆ applyForward() [2/3]

◆ applyForward() [3/3]

◆ applyInverse() [1/3]

◆ applyInverse() [2/3]

◆ applyInverse() [3/3]

◆ clear()

◆ copy()

◆ copyImpl()

◆ copyPolymorphic()

◆ decompose()

◆ fromAstObject()

◆ fromString()

◆ getB()

◆ getC()

◆ getClassName()

◆ getD()

◆ getF()

◆ getI()

◆ getID()

◆ getIdent()

◆ getIsLinear()

◆ getIsSimple()

◆ getIterInverse()

◆ getL()

◆ getNIn()

◆ getNIterInverse()

◆ getNObject()

◆ getNOut()

◆ getObjSize()

◆ getRawPtr() [1/2]

◆ getRawPtr() [2/2]

◆ getRefCount()

◆ getReport()

◆ getTolInverse()

◆ getUseDefs()

◆ hasAttribute()

◆ hasForward()

◆ hasInverse()

◆ inverted()

◆ isInverted()

◆ linearApprox()

◆ lock()

Notes

◆ makeShim()

◆ operator!=()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator==()

◆ polyTran()

◆ rate()

◆ same()

◆ set()

Notes

◆ setB()

◆ setC()

◆ setD()

◆ setF()

◆ setI()

◆ setID()

◆ setIdent()

◆ setL()