casacore
MeasUDF.h
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1 //# MeasUDF.h: TaQL functions handling measures
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
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24 //# Charlottesville, VA 22903-2475 USA
25 //#
26 //# $Id$
27 
28 #ifndef MEAS_MEASUDF_H
29 #define MEAS_MEASUDF_H
30 
31 #include <casacore/casa/aips.h>
32 #include <casacore/meas/MeasUDF/EpochUDF.h>
33 
34 namespace casacore { //# NAMESPACE CASACORE - BEGIN
35 
36 // <module>
37 //
38 // <summary>
39 // TaQL user defined functions handling measures
40 // </summary>
41 
42 // <prerequisite>
43 // <li> UDFBase
44 // <li> <linkto module="Measures:description">Measures</linkto> module
45 // </prerequisite>
46 //
47 // <reviewed reviewer="" date="" demos="">
48 // </reviewed>
49 
50 // <synopsis>
51 // This module extends TaQL (the Table Query Language) with functions handling
52 // measures. Currently it can handle MDirection, MEpoch, MPosition, MFrequency,
53 // MRadialVelocity, MDoppler and MEarthMagnetic.
54 //
55 // These functions make it possible to convert one or more measures from
56 // one reference type and frame to another. For example, to convert a
57 // direction from J2000 to apparent one can specify the direction in J2000
58 // as well as a time and position to define the measure frame like:
59 // <srcblock>
60 // calc meas.app ([4h23m32.7, 34d11m54.8], "J2000",
61 // datetime(), "UTC", POSITION) from my.ms/ANTENNA
62 // </srcblock>
63 // The above example converts the given J2000 direction to apparent coordinates
64 // for the given time (current time is used) and for all positions in the
65 // POSITION column in the given ANTENNA table.
66 //
67 // As shown in the example an argument of a <src>meas</src> function can be
68 // a constant, a table column in a table. or any expression.
69 // If a table column is given, it is recognized if the column has a reference
70 // type attached to it (using the TableMeasures). In this example it
71 // would be recognized that the positions in the POSITION column are given
72 // as, say, WGS84.
73 // <br>For constants the reference type can be given in case it differs from
74 // the default type. In the example UTC is specified for the time (was not
75 // necessary because it is the default).
76 
77 // <note>
78 // The meas library will be loaded dynamically by TaQL when such a function
79 // is used. Therefore it is important that the library and the other casacore
80 // libraries are built shared.
81 // <br>It is also important that the library can be found in the
82 // (DY)LD_LIBRARY_PATH.
83 // </note>
84 // </synopsis>
85 //
86 // <motivation>
87 // It is very handy to be able to convert measures in tools that
88 // deal with various table columns (e.g. TaQL, TablePlot, pyrap).
89 // </motivation>
90 
91 //# <todo asof="1997/02/01">
92 //# </todo>
93 
94 // </module>
95 
96 
97 } //# NAMESPACE CASACORE - END
98 
99 #endif
this file contains all the compiler specific defines
Definition: mainpage.dox:28