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Gaussian2DParam.h
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//# Gaussian2DParam.h: Parameter handling for 2 dimensional Gaussian class
//# Copyright (C) 2001,2002,2003
//# Associated Universities, Inc. Washington DC, USA.
//#
//# This library is free software; you can redistribute it and/or modify it
//# under the terms of the GNU Library General Public License as published by
//# the Free Software Foundation; either version 2 of the License, or (at your
//# option) any later version.
//#
//# This library is distributed in the hope that it will be useful, but WITHOUT
//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
//# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
//# License for more details.
//#
//# You should have received a copy of the GNU Library General Public License
//# along with this library; if not, write to the Free Software Foundation,
//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
//#
//# Correspondence concerning AIPS++ should be addressed as follows:
//# Internet email: casa-feedback@nrao.edu.
//# Postal address: AIPS++ Project Office
//# National Radio Astronomy Observatory
//# 520 Edgemont Road
//# Charlottesville, VA 22903-2475 USA
#ifndef SCIMATH_GAUSSIAN2DPARAM_H
#define SCIMATH_GAUSSIAN2DPARAM_H
#include <casacore/casa/aips.h>
#include <casacore/casa/Arrays/ArrayFwd.h>
#include <casacore/scimath/Functionals/Function.h>
#include <casacore/casa/BasicSL/String.h>
namespace casacore { //# NAMESPACE CASACORE - BEGIN
// <summary> Parameter handling for 2 dimensional Gaussian class
// </summary>
// <use visibility=local>
// <reviewed reviewer="mwieringa" date="1996/10/d24" tests="tGaussian2D">
// </reviewed>
// <prerequisite>
// <li> <linkto class="FunctionParam">FunctionParam</linkto> class
// <li> <linkto class="Function">Function</linkto> class
// </prerequisite>
// <etymology>
// A 2-dimensional Gaussian's parameters.
// </etymology>
// <synopsis>
// A <src>Gaussian2D</src> is described by a height, center, and width,
// and position angle.
// The width of the Gaussian (for the constructors or the <src> setWidth
// </src> function) is always specified in terms of the full width at half
// maximum (FWHM). The major axis is parallel with the y axis when the
// position angle is zero. The major axis will always have a larger width
// than the minor axis.
//
// It is not possible to set the width of the major axis (using the <src>
// setMajorAxis </src> function) smaller than the width of the current minor
// axis. Similarly it is not possible to set the width of the minor axis
// (using the <src> setMinorAxis </src> function) to be larger than the
// current major axis. Exceptions are thrown if these rules are violated or
// if either the major or minor axis is set to a non-positive width. To
// set both axis in one hit use the <src> setWidth </src> function. All
// these restrictions can be overcome when the parameters interface is used
// (see below).
//
// The position angle is the angle between the y axis and the major axis and
// is measured counter-clockwise, so a position angle of 45 degrees rotates
// the major axis to the line where <src>y=-x</src>.
// The position angle is always
// specified and returned in radians. When using the <src> setPA </src>
// function its value must be between -2pi and + 2pi, and the returned value
// from the <src> pa </src> function will always be a value between 0 and
// pi.
//
// The axial ratio can be used as an alternative to specifying the width of
// the minor axis. It is the ratio between the minor and major axis
// widths. The axial ratio is constrained to be between zero and one, and
// specifying something different (using setAxialRatio) will throw an
// exception.
//
// The peak height of the Gaussian can be specified at construction time or
// by using the <src> setHeight </src> function. Alternatively the <src>
// setFlux </src> function can be used to implicitly set the peak height by
// specifying the integrated area under the Gaussian. The height (or flux)
// can be positive, negative or zero, as this class makes no assumptions on
// what quantity the height represents.
//
// <note role=tip> Changing the width of the Gaussian will not affect
// its peak height but will change its flux. So you should always set the
// width before setting the flux. </note>
//
// The parameter interface (see
// <linkto class="FunctionParam">FunctionParam</linkto> class),
// is used to provide an interface to the
// <linkto module="Fitting"> Fitting </linkto> classes.
//
// There are 6 parameters that are used to describe the Gaussian:
// <ol>
// <li> The height of the Gaussian. This is identical to the value
// returned using the <src> height </src> member function.
// <li> The center of the Gaussian in the x direction. This is identical to
// the value returned using the <src> xCenter </src> member function.
// <li> The center of the Gaussian in the y direction. This is identical to
// the value returned using the <src> yCenter </src> member function.
// <li> The width (FWHM) of the Gaussian on one axis. Initially this will be
// the major axis, but if the parameters are adjusted by a Fitting
// class, it may become the axis with the smaller width. To aid
// convergence of the non-linear fitting routines this parameter is
// allowed to be negative. This does not affect the shape of the
// Gaussian as the squares of the widths are used when evaluating the
// function.
// <li> A modified axial ratio. This parameter is the ratio of the width on
// the 'other' axis (which initially is the minor axis) and axis given
// by parameter 4. Because these internal widths are allowed to be
// negative and because there is no constraints on which axis is the
// larger one the modified axial ratio is not constrained to be between
// zero and one.
// <li> The rotation angle. This represents the angle (in radians) between
// the axis used by parameter 4, and the y axis, measured
// counterclockwise. If parameter 4 represents the major axis width
// then this parameter will be identical to the position angle,
// otherwise it will be different by 90 degrees. The tight constraints
// on the value of the rotation angle enforced by the setPA() function
// are relaxed so that any value between -6000 and 6000 is allowed. It
// is still interpreted in radians.
// </ol>
//
// An enumeration for the <src>HEIGHT</src>, <src>XCENTER</src>,
// <src>YCENTER</src>, <src>YWIDTH</src>, <src>RATIO</src>, <src>PANGLE</src>
// parameter index is provided, enabling the setting
// and reading of parameters with the <src>[]</src> operator. The
// <src>mask()</src> methods can be used to check and set the parameter masks.
//
// This class is in general used implicitly by the <src>Gaussian2D</src>
// class only.
//
// <note role=tip>
// Other points to bear in mind when fitting this class to measured data
// are:
// <ul>
// <li> If you need to fit a circular Gaussian to data you MUST set the
// axial ratio to one, and mask the position angle and axial ratio
// parameters. This avoids rank deficiency in the fitting routines as
// the position angle is meaningless when the major and minor axis are
// equal.
// <li> If fitting an elliptical Gaussian your initial model should not be a
// circular Gaussian.
// </ul>
// </note>
//
// </synopsis>
// <example>
// <srcblock>
// Gaussian2D<Double> g(10.0, 0.0, 0.0, 2.0, 1.0, 0.0);
// Vector<Double> x(2);
// x(0) = 1.0; x(1) = 0.5;
// cout << "g(" << x(0) << "," << x(1) << ") = " << g(x) << endl;
// </srcblock>
// </example>
// <motivation>
// Gaussian2D objects allow us to represent models of
// the sky in a more conventional way than the generic interface used in the
// GaussianND class does.
// </motivation>
// <templating arg=T>
// <li> T should have standard numerical operators and exp() function. Current
// implementation only tested for real types (and AutoDiff of them).
// </templating>
// <thrown>
// <li> Assertion in debug mode if attempt is made to set a negative width
// <li> AipsError if incorrect parameter number specified.
// </thrown>
// <todo asof="2001/08/19">
// <li> Gaussians that know about their DFT's could be required eventually.
// </todo>
template<class T> class Gaussian2DParam : public Function<T>
{
public:
//# Enumerations
enum { HEIGHT=0, XCENTER, YCENTER, YWIDTH, RATIO, PANGLE};
//# Constructors
// Constructs the two dimensional Gaussians. Defaults:
// height=1, center=0, width(FWHM)=1, pa=0.
// <group>
Gaussian2DParam();
Gaussian2DParam(const T &height, const Vector<T> &center,
const Vector<T> &width, const T &pa);
Gaussian2DParam(const T &height, const T &xCenter, const T &yCenter,
const T &majorAxis, const T &axialRatio,
const T &pa);
// </group>
// Copy constructor (deep copy)
// <group>
Gaussian2DParam(const Gaussian2DParam<T> &other);
template <class W>
Gaussian2DParam(const Gaussian2DParam<W> &other) :
Function<T>(other),
fwhm2int(T(1.0)/sqrt(log(T(16.0)))) { majorAxis(); setPA(PA()); }
// </group>
// Copy assignment (deep copy)
Gaussian2DParam<T> &operator=(const Gaussian2DParam<T> &other);
// Destructor
virtual ~Gaussian2DParam();
//# Operators
// Variable dimensionality
virtual uInt ndim() const { return 2; }
//# Member functions
// Give name of function
virtual const String &name() const { static String x("gaussian2d");
return x; }
// Get or set the peak height of the Gaussian
// <group>
T height() const { return param_p[HEIGHT]; }
void setHeight(const T &height) { param_p[HEIGHT] = height; }
// </group>
// Get or set the analytical integrated area underneath the Gaussian.
// Use these functions as an alternative to the height functions.
// <group>
T flux() const;
void setFlux(const T &flux);
// </group>
// Get or set the center ordinate of the Gaussian
// <group>
Vector<T> center() const;
void setCenter(const Vector<T> &center);
T xCenter() const { return param_p[XCENTER]; }
void setXcenter(const T &cnter) { param_p[XCENTER] = cnter; }
T yCenter() const { return param_p[YCENTER]; }
void setYcenter(const T &cnter) { param_p[YCENTER] = cnter; }
// </group>
// Set or get the FWHM of the Gaussian.
// <group>
Vector<T> width() const;
void setWidth(const Vector<T> &width);
T majorAxis() const;
void setMajorAxis(const T &width);
T minorAxis() const;
void setMinorAxis(const T &width);
T axialRatio() const;
void setAxialRatio(const T &axialRatio);
// </group>
// Set/get the rotation angle (orientation) of the Gaussian. PA is given
// in radians counterclockwise.
// <group>
T PA() const;
void setPA(const T &pa);
// </group>
protected:
// Constant to scale halfwidth at 1/e to FWHM
T fwhm2int;
// cached vale of the PA
mutable T thePA;
// cached values of the cos and sine of thePA
// <group>
mutable T theSpa;
mutable T theCpa;
// </group>
// cached vale of the Xwidth = ratio*theYwidth;
mutable T theXwidth;
//# Make members of parent classes known.
protected:
using Function<T>::param_p;
public:
using Function<T>::nparameters;
};
} //# NAMESPACE CASACORE - END
#ifndef CASACORE_NO_AUTO_TEMPLATES
#include <casacore/scimath/Functionals/Gaussian2DParam.tcc>
#endif //# CASACORE_NO_AUTO_TEMPLATES
#endif
casacore::Function::param_p
FunctionParam< T > param_p
The parameters and masks.
Definition Function.h:330
casacore::Function::Function
Function()
Constructors.
Definition Function.h:210
casacore::Function::nparameters
uInt nparameters() const
Returns the number of parameters.
Definition Function.h:228
casacore::Gaussian2DParam::theXwidth
T theXwidth
cached vale of the Xwidth = ratio*theYwidth;
Definition Gaussian2DParam.h:286
casacore::Gaussian2DParam::height
T height() const
Get or set the peak height of the Gaussian.
Definition Gaussian2DParam.h:235
casacore::Gaussian2DParam::Gaussian2DParam
Gaussian2DParam(const Gaussian2DParam< W > &other)
Definition Gaussian2DParam.h:212
casacore::Gaussian2DParam::name
virtual const String & name() const
Give name of function.
Definition Gaussian2DParam.h:230
casacore::Gaussian2DParam::thePA
T thePA
cached vale of the PA
Definition Gaussian2DParam.h:279
casacore::Gaussian2DParam::setCenter
void setCenter(const Vector< T > &center)
casacore::Gaussian2DParam::majorAxis
T majorAxis() const
casacore::Gaussian2DParam::yCenter
T yCenter() const
Definition Gaussian2DParam.h:252
casacore::Gaussian2DParam::center
Vector< T > center() const
Get or set the center ordinate of the Gaussian.
casacore::Gaussian2DParam::theCpa
T theCpa
Definition Gaussian2DParam.h:283
casacore::Gaussian2DParam::~Gaussian2DParam
virtual ~Gaussian2DParam()
Destructor.
casacore::Gaussian2DParam::Gaussian2DParam
Gaussian2DParam(const T &height, const T &xCenter, const T &yCenter, const T &majorAxis, const T &axialRatio, const T &pa)
casacore::Gaussian2DParam::width
Vector< T > width() const
Set or get the FWHM of the Gaussian.
casacore::Gaussian2DParam::fwhm2int
T fwhm2int
Constant to scale halfwidth at 1/e to FWHM.
Definition Gaussian2DParam.h:277
casacore::Gaussian2DParam::PA
T PA() const
Set/get the rotation angle (orientation) of the Gaussian.
casacore::Gaussian2DParam::setPA
void setPA(const T &pa)
casacore::Gaussian2DParam::Gaussian2DParam
Gaussian2DParam(const Gaussian2DParam< T > &other)
Copy constructor (deep copy).
casacore::Gaussian2DParam::Gaussian2DParam
Gaussian2DParam()
Constructs the two dimensional Gaussians.
casacore::Gaussian2DParam::theSpa
T theSpa
cached values of the cos and sine of thePA
Definition Gaussian2DParam.h:282
casacore::Gaussian2DParam::setMinorAxis
void setMinorAxis(const T &width)
casacore::Gaussian2DParam::setFlux
void setFlux(const T &flux)
casacore::Gaussian2DParam::setYcenter
void setYcenter(const T &cnter)
Definition Gaussian2DParam.h:253
casacore::Gaussian2DParam::setHeight
void setHeight(const T &height)
Definition Gaussian2DParam.h:236
casacore::Gaussian2DParam::ndim
virtual uInt ndim() const
Variable dimensionality.
Definition Gaussian2DParam.h:226
casacore::Gaussian2DParam::setMajorAxis
void setMajorAxis(const T &width)
casacore::Gaussian2DParam::setAxialRatio
void setAxialRatio(const T &axialRatio)
casacore::Gaussian2DParam::setWidth
void setWidth(const Vector< T > &width)
casacore::Gaussian2DParam::operator=
Gaussian2DParam< T > & operator=(const Gaussian2DParam< T > &other)
Copy assignment (deep copy).
casacore::Gaussian2DParam::axialRatio
T axialRatio() const
casacore::Gaussian2DParam::minorAxis
T minorAxis() const
casacore::Gaussian2DParam::xCenter
T xCenter() const
Definition Gaussian2DParam.h:250
casacore::Gaussian2DParam::PANGLE
@ PANGLE
Definition Gaussian2DParam.h:194
casacore::Gaussian2DParam::HEIGHT
@ HEIGHT
Definition Gaussian2DParam.h:194
casacore::Gaussian2DParam::XCENTER
@ XCENTER
Definition Gaussian2DParam.h:194
casacore::Gaussian2DParam::RATIO
@ RATIO
Definition Gaussian2DParam.h:194
casacore::Gaussian2DParam::YCENTER
@ YCENTER
Definition Gaussian2DParam.h:194
casacore::Gaussian2DParam::YWIDTH
@ YWIDTH
Definition Gaussian2DParam.h:194
casacore::Gaussian2DParam::setXcenter
void setXcenter(const T &cnter)
Definition Gaussian2DParam.h:251
casacore::Gaussian2DParam::flux
T flux() const
Get or set the analytical integrated area underneath the Gaussian.
casacore::Gaussian2DParam::Gaussian2DParam
Gaussian2DParam(const T &height, const Vector< T > &center, const Vector< T > &width, const T &pa)
casacore::String
String: the storage and methods of handling collections of characters.
Definition String.h:223
casacore::Vector
Definition Vector.h:82
casacore
this file contains all the compiler specific defines
Definition mainpage.dox:28
casacore::pa
LatticeExprNode pa(const LatticeExprNode &left, const LatticeExprNode &right)
This function finds 180/pi*atan2(left,right)/2.
casacore::uInt
unsigned int uInt
Definition aipstype.h:49
casacore::sqrt
LatticeExprNode sqrt(const LatticeExprNode &expr)
casacore::log
LatticeExprNode log(const LatticeExprNode &expr)