/usr/include/casacore/measures/TableMeasures.h is in casacore-dev 2.2.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 | //# TableMeasures.h: Create Measure and Quantum columns Tables.
//# Copyright (C) 1996,1997,1998,1999,2000,2001
//# 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: aips2-request@nrao.edu.
//# Postal address: AIPS++ Project Office
//# National Radio Astronomy Observatory
//# 520 Edgemont Road
//# Charlottesville, VA 22903-2475 USA
//#
//# $Id$
#ifndef MEASURES_TABLEMEASURES_H
#define MEASURES_TABLEMEASURES_H
#include <casacore/casa/aips.h>
#include <casacore/measures/TableMeasures/ArrayMeasColumn.h>
#include <casacore/measures/TableMeasures/ArrayQuantColumn.h>
#include <casacore/measures/TableMeasures/ScalarMeasColumn.h>
#include <casacore/measures/TableMeasures/ScalarQuantColumn.h>
#include <casacore/measures/TableMeasures/TableMeasDesc.h>
#include <casacore/measures/TableMeasures/TableMeasOffsetDesc.h>
#include <casacore/measures/TableMeasures/TableMeasRefDesc.h>
#include <casacore/measures/TableMeasures/TableMeasValueDesc.h>
#include <casacore/measures/TableMeasures/TableQuantumDesc.h>
namespace casacore { //# NAMESPACE CASACORE - BEGIN
// <module>
// <summary>
// Create and use scalar and array columns of Quanta and Measures in Tables.
// </summary>
// <prerequisite>
// <li> <linkto module=Measures>Measures</linkto>
// <li> <linkto module=Tables>Tables</linkto>
// </prerequisite>
// <reviewed reviewer="Bob Garwood" date="1999/12/23">
// </reviewed>
// <etymology>
// Table columns containing Measures and Quanta
// </etymology>
// <synopsis>
// The TableMeasures system exists to provide a way of creating (defining)
// Measure and Quantum Table columns thus enabling the direct storage of
// Quanta and Measures in Casacore Tables.
// <p>
// Defining Quantum and Measure columns is a once only operation (for each
// column). It can be seen as an extension to the existing Column Descriptor
// mechanism which adds a column of a specified type to a table. The
// <linkto><class=TableMeasDesc>TableMeasDesc</linkto> and
// <linkto><class=TableQuantumDesc>TableQuantumDesc</linkto> class
// hierarchies are used to define Measure and Quantum columns.
// <p>
// Once defined, Measure and Quantum column objects are used to access a
// column for reading and writing of Measures and Quanta. For Quantum
// column objects see the class
// <linkto><class=ScalarQuantColumn>ScalarQuantColumn</linkto> and
// <linkto><class=ArrayQuantColumn>ArrayQuantColumn</linkto>. For
// Measure column objects see
// <linkto><class=ScalarMeasColumn>ScalarMeasColumn</linkto> and
// <linkto><class=ArrayMeasColumn>ArrayMeasColumn</linkto>.
//
// <h3>Conversions</h3>
// The classes accessing the data use the underlying
// <linkto module=Quanta>Quanta</linkto> or
// <linkto module=Measures>Measures</linkto> classes to convert
// the units or references of the measures or quanta.
// The TableMeasures classes do not test if a conversion is possible.
// <br>In general one can say that about every unit conversion is possible.
// The <linkto class=Unit>Unit</linkto> class adjusts units as needed.
// <br>Conversions of Measures are only possible if enough information
// is supplied for the measure's reference.
// <br>Take a look at the abovementioned modules to find out about conversions.
//
// <h3>Performance</h3>
// Using the TableMeasures classes makes it easier to deal with
// measures in tables. However, there is a performance penalty
// compared to handling the values directly in the table using
// the Tables classes <linkto class=ScalarColumn>ScalarColumn</linkto>
// and <linkto class=ArrayColumn>ArrayColumn</linkto>.
//
// The performance of the TableMeasures classes depends on how the
// measures are stored; thus if a fixed or variable offset and reference
// are used.
// Of course, it also depends on whether the measures have to be
// converted before they can be stored.
// <br>The TableMeasures classes are always slower than the Tables classes,
// but they offer more convenience.
// In general one can say that for large tables it is better to use
// the Tables classes directly to put/get the data.
// However, even when putting directly using the Tables classes, the
// column itself should be defined as a TableMeasure. In that way there
// is one standard way of defining columns as table measures.
// <br>For example, the TIME column in a MeasurementSet should be handled
// directly uisng the Tables classes (because it is so large).
// On the other hand, the FIELD table is very small and it may make life
// easier to handle its columns through the TableMeasures classes.
//
// In a test putting an array of quanta using class
// <linkto class=ArrayQuantColumn>ArrayQuantColumn</linkto> took
// about 5 times as long as doing it directly using class
// <linkto class=ArrayColumn>ArrayColumn</linkto>. The quantum column
// had variable units. so for each row the unit had to be written as well.
// Reading it back took about 3 times as long.
// <br>When using a qunatum column with fixed units, putting took about
// 2.5 times as long as using <src>ArrayColumn</src> directly.
// Each put involved a unit conversion.
// Reading it back took only 10% more than when using <src>ArrayColumn</src>.
//
// </synopsis>
// <motivation>
// The standard Casacore Table system does not directly support Quantum and
// Measure columns. These classes overcome this limitation.
// </motivation>
//# <todo asof="">
//# </todo>
// </module>
} //# NAMESPACE CASACORE - END
#endif
|