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SincFunction.h
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1//# SincFunction.h: A one dimensional sin(x)/x
2//# Copyright (C) 2002,2005
3//# Associated Universities, Inc. Washington DC, USA.
4//#
5//# This library is free software; you can redistribute it and/or modify it
6//# under the terms of the GNU Library General Public License as published by
7//# the Free Software Foundation; either version 2 of the License, or (at your
8//# option) any later version.
9//#
10//# This library is distributed in the hope that it will be useful, but WITHOUT
11//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12//# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
13//# License for more details.
14//#
15//# You should have received a copy of the GNU Library General Public License
16//# along with this library; if not, write to the Free Software Foundation,
17//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
18//#
19//# Correspondence concerning AIPS++ should be addressed as follows:
20//# Internet email: aips2-request@nrao.edu.
21//# Postal address: AIPS++ Project Office
22//# National Radio Astronomy Observatory
23//# 520 Edgemont Road
24//# Charlottesville, VA 22903-2475 USA
25//#
26//# $Id$
27
28#ifndef SCIMATH_SINCFUNCTION_H
29#define SCIMATH_SINCFUNCTION_H
30
31//# Includes
32#include <casacore/casa/aips.h>
33#include <casacore/scimath/Functionals/SincParam.h>
34#include <casacore/scimath/Functionals/Function.h>
35
36namespace casacore { //# NAMESPACE CASACORE - BEGIN
37
38//# Forward declarations
39
40// <summary> A one dimensional sin(x)/x
41// </summary>
42
43// <use visibility=export>
44
45// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="tFunctionHolder"
46// demos="">
47// </reviewed>
48
49// <prerequisite>
50// <li> <linkto class="SincParam">SincParam</linkto>
51// <li> <linkto class="Function">Function</linkto>
52// </prerequisite>
53
54// <etymology>
55// A 1-dimensional sinc function.
56// </etymology>
57
58// <synopsis>
59// A <src>Sinc</src> is described by a height, a center and a width
60// (halfwidth). The value is:
61// <srcblock>
62// let y = (x-center)/width
63// height (x == center)
64// height*sin(pi*y)/(pi*y) (x |= center)
65// </srcblock>
66// The parameters are enumerated by HEIGHT, CENTER and WIDTH. They have
67// default values of (1, 0, 1).
68// </synopsis>
69//
70// <example>
71// <srcblock>
72// SincFunction<Double> sf(5.0, 25.0, 7);
73// sf(25); // = 5.0
74// </srcblock>
75// </example>
76
77// <templating arg=T>
78// <li> T should have standard numerical operators
79// </templating>
80
81// <thrown>
82// <li> AipsError if incorrect parameter number specified.
83// </thrown>
84//
85
86template<class T> class SincFunction : public SincParam<T>
87{
88public:
89 //# Constructors
90 // Constructs the SincFunction, Defaults:
91 // height=1, center=0, width=1.
92 // <note role=warning> Could not use default arguments
93 // that worked both with gcc and IRIX </note>
94 // <group>
96 explicit SincFunction(const T &height) :
97 SincParam<T>(height) {}
98 SincFunction(const T &height, const T &center) :
99 SincParam<T>(height, center) {}
100 SincFunction(const T &height, const T &center, const T &width) :
101 SincParam<T>(height, center, width) {}
102 // </group>
103
104 // Copy constructor (deep copy)
105 // <group>
106 SincFunction(const SincFunction<T> &other) : SincParam<T>(other) {}
107 template <class W>
108 SincFunction(const SincFunction<W> &other) : SincParam<T>(other) {}
109 // </group>
110
111 // Copy assignment (deep copy)
113 SincParam<T>::operator=(other); return *this; }
114
115 // Destructor
116 virtual ~SincFunction() {}
117
118 //# Operators
119 // Evaluate the Sinc at <src>x</src>.
120 // If a vector is used as the argument only its first element is used.
121 // <group>
122 virtual T eval(typename Function<T>::FunctionArg x) const;
123 // </group>
124
125 //# Member functions
126 // Return a copy of this object from the heap. The caller is responsible
127 // for deleting this pointer.
128 // <group>
129 virtual Function<T> *clone() const { return new SincFunction<T>(*this); }
134 // </group>
135
136 //# Make members of parent classes known.
137protected:
138 using SincParam<T>::param_p;
139public:
140 using SincParam<T>::nparameters;
141 using SincParam<T>::CENTER;
142 using SincParam<T>::WIDTH;
143 using SincParam<T>::HEIGHT;
144};
145
146
147} //# NAMESPACE CASACORE - END
148
149#ifndef CASACORE_NO_AUTO_TEMPLATES
150#include <casacore/scimath/Functionals/SincFunction.tcc>
151#endif //# CASACORE_NO_AUTO_TEMPLATES
152#endif
FunctionParam< T > param_p
The parameters and masks.
Definition Function.h:332
uInt nparameters() const
Returns the number of parameters.
Definition Function.h:230
SincFunction(const SincFunction< T > &other)
Copy constructor (deep copy)
SincFunction(const T &height)
SincFunction(const SincFunction< W > &other)
SincFunction()
Constructs the SincFunction, Defaults: height=1, center=0, width=1.
SincFunction(const T &height, const T &center)
SincFunction(const T &height, const T &center, const T &width)
virtual ~SincFunction()
Destructor.
virtual Function< T > * clone() const
Return a copy of this object from the heap.
virtual Function< typename FunctionTraits< T >::BaseType > * cloneNonAD() const
virtual Function< typename FunctionTraits< T >::DiffType > * cloneAD() const
virtual T eval(typename Function< T >::FunctionArg x) const
Evaluate the Sinc at x.
SincFunction< T > & operator=(const SincFunction< T > &other)
Copy assignment (deep copy)
SincParam< T > & operator=(const SincParam< T > &other)
Copy assignment (deep copy)
this file contains all the compiler specific defines
Definition mainpage.dox:28