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EpochEngine.h
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1//# EpochEngine.h: Engine for TaQL UDF Epoch conversions
2//# Copyright (C) 2011
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 MEAS_EPOCHENGINE_H
29#define MEAS_EPOCHENGINE_H
30
31//# Includes
32#include <casacore/casa/aips.h>
33#include<casacore/meas/MeasUDF/MeasEngine.h>
34#include <casacore/measures/Measures/MEpoch.h>
35#include <casacore/measures/Measures/MCEpoch.h>
36#include <casacore/measures/Measures/MeasConvert.h>
37
38namespace casacore {
39
40 //# Forward declarations
41 class PositionEngine;
42
43
44// <summary>
45// Engine for TaQL UDF Epoch conversions
46// </summary>
47
48// <use visibility=export>
49
50// <reviewed reviewer="" date="" tests="tMeas.cc">
51// </reviewed>
52
53// <prerequisite>
54//# Classes you should understand before using this one.
55// <li> EngineBase
56// </prerequisite>
57
58// <synopsis>
59// EpochEngine defines Engines (user defined functions) that can be used in TaQL
60// to convert Measures for epochs.
61// In this way such derived values appear to be ordinary TaQL functions.
62//
63// In TaQL these functions can be called like:
64// <srcblock>
65// meas.epoch (toref, time, fromref)
66// meas.last (time, fromref, pos, posref)
67// For example,
68// meas.epoch ('UTC', 1e9 s, 'WGS84')
69// </srcblock>
70// <ul>
71// <li>
72// <src>toref</src> is a single constant string.
73// <li>
74// <src>pos</src> can have various value types. A single numeric array is
75// a series of RA,DEC in J2000. If given as a set, the last argument of the
76// set can be the reference types of the values in the set. The values can
77// be strings (indicating planetary objects) or value pairs giving lon,lat.
78// The default reference type is J2000.
79// </ul>
80// All functions have data type double and unit radian.
81
82// A epoch can also be a table column which usually knows its type.
83// It can also be an expression (e.g. EPOCH[0,]) which also knows the type.
84// </synopsis>
85
86// <motivation>
87// It makes it possible to handle measures in TaQL.
88// </motivation>
89
90 class EpochEngine: public MeasEngine<MEpoch>
91 {
92 public:
94
95 virtual ~EpochEngine();
96
97 // Tell if the fraction has to be used for sidereal times.
98 Bool sidFrac() const
99 { return itsSidFrac; }
100
101 // Get the values.
103
104 // Get the epochs.
106
107 // Handle the argument(s) giving the input epochs and reference type.
108 // The epoch can be a column in a table.
109 void handleEpoch (std::vector<TENShPtr>& args,
110 uInt& argnr);
111
112 // Set the MeasConvert object.
114
115 // Set the possible position engine.
116 // It can be done only once.
118
119 private:
120 // Strip a possible prefix from the epoch type.
121 virtual String stripMeasType (const String& type);
122 virtual void handleValues (TableExprNode& operand,
123 const TableExprId& id,
124 Array<MEpoch>& epochs);
125
126 //# Data members.
127 Bool itsSidFrac; //# T = fraction for sidereal
128 MeasFrame itsFrame; //# frame used by converter
131 };
132
133} //end namespace
134
135#endif
PositionEngine * itsPositionEngine
void setPositionEngine(PositionEngine &engine)
Set the possible position engine.
virtual void handleValues(TableExprNode &operand, const TableExprId &id, Array< MEpoch > &epochs)
Let a derive class handle the values.
Array< MEpoch > getEpochs(const TableExprId &id)
Get the epochs.
Array< Double > getArrayDouble(const TableExprId &id)
Get the values.
void setConverter(MEpoch::Types toType, Bool sidFrac)
Set the MeasConvert object.
MEpoch::Convert itsConverter
void handleEpoch(std::vector< TENShPtr > &args, uInt &argnr)
Handle the argument(s) giving the input epochs and reference type.
virtual String stripMeasType(const String &type)
Strip a possible prefix from the epoch type.
Bool sidFrac() const
Tell if the fraction has to be used for sidereal times.
Definition EpochEngine.h:98
Types
Types of known MEpochs Caution: The order defines the order in the translation matrix in the MCEpoch...
Definition MEpoch.h:117
String: the storage and methods of handling collections of characters.
Definition String.h:225
this file contains all the compiler specific defines
Definition mainpage.dox:28
unsigned int uInt
Definition aipstype.h:51
bool Bool
Define the standard types used by Casacore.
Definition aipstype.h:42