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FITSKeywordUtil.h
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1//# FITSKeywordUtil.h: Class of static functions to help with FITS Keywords.
2//# Copyright (C) 2002
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
30#ifndef FITS_FITSKEYWORDUTIL_H
31#define FITS_FITSKEYWORDUTIL_H
32
33#include <casacore/casa/aips.h>
34#include <casacore/casa/Arrays/ArrayFwd.h>
35
36namespace casacore { //# NAMESPACE CASACORE - BEGIN
37
38class ConstFitsKeywordList;
39class FitsKeywordList;
40class RecordInterface;
41class IPosition;
42class String;
43
44// <summary>
45// A class with static functions to help deal with FITS Keywords.
46// </summary>
47
48// <use visibility=export>
49
50// <reviewed reviewer="Eric Sessoms" date="2002/08/19" tests="tFITSKeywordUtil.cc">
51// </reviewed>
52
53// <prerequisite>
54// <li> General knowledge of FITS, and particularly FITS keywords, is
55// assumed.
56// <li> Presumably you are using this class in conjunction
57// with the "native"
58// <linkto class=FitsKeywordList>FitsKeywordList</linkto>
59// <li> You also need to understand the
60// <linkto class=RecordInterface>RecordInterface</linkto>
61// class.
62// </prerequisite>
63//
64// <etymology>
65// This is a collection of static utility functions for use with FITS
66// keywords.
67// </etymology>
68//
69// <synopsis>
70// This class provides functions to conveniently interconvert between Casacore
71// types and a FitsKeywordList which is needed by the native FITS classes.
72// It is more convenient to maintain the list within Casacore
73// as a Record, so we only need methods to turn a FitsKeywordList into a
74// Record, and vice versa.
75//
76// Note that it is not necessary to construct a FITSKeywordUtil object
77// since you can use its static functions directly.
78// </synopsis>
79//
80// <example>
81// This example shows how you put values from a Record into a
82// FItsKeywordList.
83// <srcblock>
84// Record rec;
85// rec.define("hello", 6.5);
86// rec.define("world", True);
87// Vector<Int> naxis(5);
88// naxis(0) = 128;
89// naxis(1) = 64;
90// naxis(2) = 32;
91// naxis(3) = 16;
92// naxis(4) = 8;
93// rec.define("naxis", naxis);
94// // fields can have comments
95// rec.setComment("hello","A comment for HELLO");
96// // Add a comment to the rec
97// FITSKeywordUtil::addComment(rec,"My comment goes here");
98// // Create an empty FitsKeywordList, containing only "SIMPLE=T"
99// FitsKeywordList kwl = FITSKeywordUtil::makeKeywordList();
100// // and add the fields in rec to this list
101// FITSKeywordUtil::addKeywords(kwl, rec);
102// </srcblock>
103// </example>
104//
105// <example>
106// This example shows how you extract fits keywords into a Record.
107// <srcblock>
108// Record rec;
109// FitsKeywordList kwl;
110// ConstFitsKeywordList kwlRO;
111// Vector<String> ignore(1);
112// ignore(1)= "simple"; // ignore the SIMPLE keyword
113// FITSKeywordUtil::getKeywords(rec, kwlRO, ignore);
114// </srcblock>
115// </example>
116//
117// <motivation>
118// The FitsKeywordList class can be somewhat tedious to use, as it deals with,
119// e.g., char* pointers rather than Strings. This class makes it easy to
120// interconvert between FITS keywords and Casacore types.
121// </motivation>
122//
123// <todo asof="2000/06/21">
124// <li> Get/set history as a vector of strings as well.
125// <li> This could be a namespace rather than a class.
126// </todo>
127
129{
130public:
131 // Make an initial FitsKeywordList for either a FITS primary header
132 // or a FITS extension header (image or table). A primary header
133 // requires "SIMPLE = T", an extension header "XTENSION = IMAGE "
134 // or "XTENSION = BINTABLE " for image or table, respectively.
135 // This is required of any FITS keyword list. This is provided as
136 // a convenience so that you do not have to know anything about the class
137 // <linkto class=FitsKeywordList>FitsKeywordList</linkto>.
138 static FitsKeywordList makeKeywordList(Bool primHead=True, Bool binImage=True);
139
140 // Add the fields from in to the out FitsKeywordList as keywords.
141 // Upcases field names, turns arrays into indexed keywords, tries to interleave
142 // e.g. crval, crpix, etc.
143 // COMMENT* are standalone comments, and HISTORY* are history cards.
144 // (COMMENT and HISTORY may be of any capitalization). Note however that
145 // you will generally add History keywords with the class
146 // <linkto class=FITSHistoryUtil>FITSHistoryUtil</linkto>.
147 // Returns False in the following instances:
148 // <ul>
149 // <li> The value of a string field is longer than 68 characters. The value is truncated.
150 // <li> An illegal type for a FITS keyword (e.g. Complex). The field is ignored.
151 // <li> An array field has more than 2 dimensions. The field is stored as a vector.
152 // <li> An array field name is too long to hold the name and the index characters. The name is truncated.
153 // <li> Too many rows or columns for a 2D array (first 999 in each are used).
154 // <li> Too many elements in a 1D array (first 999 are used).
155 // <li> A field is neither a scalar or an array (e.g. a record). The field is ignored.
156 // </ul>
158
159 // Extract keywords from in and define them in out.
160 // Output field names are downcased. Keywords matching
161 // the names in ignore (which are treated as regular expressions) are
162 // not created in out. This test happens after the field names
163 // have been downcased.
164 // All indexed keywords will be ignored if the root name is in the ignore
165 // vector (e.g. NAXIS implies NAXIS4 and other indexed NAXIS keywords
166 // are ignored).
167 // By default history keywords are ignored, since they
168 // should be handled in class
169 // <linkto class=FITSHistoryUtil>FITSHistoryUtil</linkto>.
170 // This always returns True.
172 const Vector<String> &ignore,
173 Bool ignoreHistory=True);
174
175
176 // Remove some keywords from a record. This can be useful
177 // if, e.g., you first need to construct a coordinate system from the
178 // header, but you later want to remove CROTA etc.
179 // The strings in the ignore vector are treated as regular expressions.
181 const Vector<String> &ignore);
182
183 // Convert a TDIMnnn keyword value into an IPosition. This returns
184 // False if the tdim string has an invalid format.
185 static Bool fromTDIM(IPosition& shape, const String& tdim);
186
187 // Convert an IPosition to a String appropriate for use as the
188 // value of a TDIMnnn keyword. This returns False if the
189 // converted string has more than 71 characters
190 // (making it impossible to be used as a string keyword value).
191 static Bool toTDIM(String& tdim, const IPosition& shape);
192
193 // Add a comment/history to the supplied record. It will automatically
194 // figure out a unique name and add it to the end. If the comment contains
195 // embedded newlines this function will break the string across multiple
196 // FITS comment entries. At present it will not however make sure that the
197 // strings are short enough (i.e. <= 72 characters per line).
198 //
199 // Note that while you can add history anywhere into header, in the actual
200 // keyword list they will always appear after the END keyword.
201
202 // Note however that you will generally manipulate History keywords with
203 // the class <linkto class=FITSHistoryUtil>FITSHistoryUtil</linkto>.
204 // <group>
205 static void addComment(RecordInterface &header, const String &comment);
206 static void addHistory(RecordInterface &header, const String &history);
207 // </group>
208};
209
210
211} //# NAMESPACE CASACORE - END
212
213#endif
list of read-only FITS keywords
Definition fits.h:951
static FitsKeywordList makeKeywordList(Bool primHead=True, Bool binImage=True)
Make an initial FitsKeywordList for either a FITS primary header or a FITS extension header (image or...
static Bool toTDIM(String &tdim, const IPosition &shape)
Convert an IPosition to a String appropriate for use as the value of a TDIMnnn keyword.
static Bool fromTDIM(IPosition &shape, const String &tdim)
Convert a TDIMnnn keyword value into an IPosition.
static void addHistory(RecordInterface &header, const String &history)
static void addComment(RecordInterface &header, const String &comment)
Add a comment/history to the supplied record.
static Bool getKeywords(RecordInterface &out, ConstFitsKeywordList &in, const Vector< String > &ignore, Bool ignoreHistory=True)
Extract keywords from in and define them in out.
static void removeKeywords(RecordInterface &out, const Vector< String > &ignore)
Remove some keywords from a record.
static Bool addKeywords(FitsKeywordList &out, const RecordInterface &in)
Add the fields from in to the out FitsKeywordList as keywords.
linked list of FITS keywords
Definition fits.h:737
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
TableExprNode shape(const TableExprNode &array)
Function operating on any scalar or array resulting in a Double array containing the shape.
Definition ExprNode.h:1987
bool Bool
Define the standard types used by Casacore.
Definition aipstype.h:42
const Bool True
Definition aipstype.h:43