casacore
MRBase.h
Go to the documentation of this file.
1//# MRBase.h: Base for Reference frame for physical measures
2//# Copyright (C) 1995,1996,1997,1998,1999,2000,2001
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//#
27//# $Id$
28
29#ifndef MEASURES_MRBASE_H
30#define MEASURES_MRBASE_H
31
32//# Includes
33#include <casacore/casa/aips.h>
34#include <casacore/measures/Measures/MeasFrame.h>
35#include <casacore/casa/iosfwd.h>
36
37namespace casacore { //# NAMESPACE CASACORE - BEGIN
38
39//# Forward Declarations
40class String;
41
42// <summary> Base for Reference frame for physical measures </summary>
43
44// <use visibility=local>
45
46// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="tMeasure" demos="">
47// </reviewed>
48
49// <prerequisite>
50// <li> <linkto class=Quantum>Quantum</linkto> class
51// <li> <linkto class=Measure>Measure</linkto> class
52// </prerequisite>
53//
54// <etymology>
55// From Measure and Reference and Base
56// </etymology>
57//
58// <synopsis>
59// MRBase is the abstract base class for reference frames.
60// Reference frames are specified (see <linkto class=Measure>Measure</linkto>)
61// as <src>Measure::Ref</src> (e.g. <src>MEpoch::Ref</src>).
62//
63// A Measure::Ref is a container for <em>type</em> indicators,
64// (e.g. <src>MDirection::J2000</src>),
65// an optional offset (e.g. beginning of year), and, if necessary, a
66// <linkto class=MeasFrame>MeasFrame</linkto>.<br>
67// A MeasFrame consists of
68// one or more Measures specifying the reference frame (e.g. an
69// <linkto class=MPosition>MPosition</linkto> for a sidereal time definition).
70// A time
71// (<linkto class=MEpoch>MEpoch</linkto>) could e.g. have a type
72// <src>MEpoch::TAI</src>, and an MEpoch as offset:
73// <srcblock>
74// MEpoch off(Quantity(40745,"d"), MEpoch::Ref(MEpoch::UTC));
75// MEpoch::Ref myref(MEpoch::TAI, off);
76// </srcblock>
77//
78// It is obvious that a circular reference between Measure and Measure::Ref
79// is possible. Therefore, each Measure has a <em>default</em> reference
80// (necessary anyway to be able to start a Measure chain). For MEpoch
81// the default is e.g. an MJD in UTC; and the default Measure for
82// an MEpoch reference is 0.<br>
83// References are copied by reference; i.e. a reference can be used in many
84// places without overhead.<br>
85// Some <src>Measure::Ref</src> could need additional conversion information
86// ( example: type of Nutation calculations). They are provided by
87// <linkto class=Aipsrc>Aipsrc</linkto> keywords. <br>
88// All constructors are related to a specific Measure, to be able to check
89// relations at compile time.
90// </synopsis>
91//
92// <example>
93// See <linkto class=Measure>Measure</linkto> for an example
94// </example>
95//
96// <motivation>
97// To gather all reference frame information in the one class.
98// </motivation>
99//
100// <todo asof="1997/04/15">
101// </todo>
102
103class MRBase {
104
105public:
106
107 //# Friends
108 friend ostream &operator<<(ostream &os, const MRBase &meas);
109
110 //# Constructors
111
112 //# Destructor
113 virtual ~MRBase();
114
115 //# Operators
116
117 //# General Member Functions
118 // Check if empty reference
119 virtual Bool empty() const = 0;
120 // Check the type of Measure the reference can be used for:<br>
121 // <src> static const String &showMe() = 0; </src>.<br>
122 // Return the type of the reference
123 // <note role=caution> the following should really be
124 // (and should be interpreted as), but
125 // compiler does not accept it:</note>
126 // <src> Ms::Types getType();</src>
127 virtual uInt getType() const = 0;
128 // Return the frame of the reference
129 virtual MeasFrame &getFrame() = 0;
130 // Return the first frame which has specified information. Checking is done in
131 // argument order.
132 // <thrown>
133 // <li> AipsError if neither reference has a frame or the proper type
134 // </thrown>
135 // <srcblock>
136 // static const MeasFrame &framePosition(const MRBase &ref1,
137 // const MRBase &ref2) = 0;
138 // static const MeasFrame &frameEpoch(const MRBase &ref1,
139 // const MRBase &ref2) = 0;
140 // static const MeasFrame &frameDirection(const MRBase &ref1,
141 // const MRBase &ref2) = 0;
142 // static const MeasFrame &frameRadialVelocity(const MRBase &ref1,
143 // const MRBase &ref2) = 0;
144 // </srcblock>
145 // Return the offset (or 0)
146 virtual const Measure* offset() const = 0;
147 // Set the type
148 // <thrown>
149 // <li> AipsError if wrong Measure
150 // </thrown>
151 // <note role=caution> the following should really be (and should be called as), but
152 // compiler does not accept it:</note>
153 // <src> void set(Ms::Types tp);</src>
154 // <group>
155 virtual void setType(uInt tp) = 0;
156 virtual void set(uInt tp) = 0;
157 // </group>
158 // Set a new offset:<br>
159 // void set(const Measure &ep);
160 // Set a new frame
161 virtual void set(const MeasFrame &mf) = 0;
162
163 // Print a Measure
164 virtual void print(ostream &os) const = 0;
165
166protected:
167
168private:
169
170 //# Data
171
172 //# Member functions
173
174};
175
176//# Global functions
177// <summary> Global functions </summary>
178// <group name=Output>
179// Output declaration
180ostream &operator<<(ostream &os, const MRBase &meas);
181// </group>
183
184} //# NAMESPACE CASACORE - END
185
186#endif
virtual uInt getType() const =0
Check the type of Measure the reference can be used for: static const String &showMe() = 0; .
virtual ~MRBase()
virtual void print(ostream &os) const =0
Print a Measure.
virtual MeasFrame & getFrame()=0
Return the frame of the reference.
virtual Bool empty() const =0
Check if empty reference.
virtual void set(uInt tp)=0
friend ostream & operator<<(ostream &os, const MRBase &meas)
virtual void set(const MeasFrame &mf)=0
Set a new offset: void set(const Measure &ep); Set a new frame.
virtual void setType(uInt tp)=0
Set the type.
virtual const Measure * offset() const =0
Return the first frame which has specified information.
this file contains all the compiler specific defines
Definition: mainpage.dox:28
ostream & operator<<(ostream &os, const IComplex &)
Show on ostream.
unsigned int uInt
Definition: aipstype.h:51
bool Bool
Define the standard types used by Casacore.
Definition: aipstype.h:42
ostream & operator<<(ostream &os, const MRBase &meas)
Output declaration.