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FITSKeywordUtil.h
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//# FITSKeywordUtil.h: Class of static functions to help with FITS Keywords.
//# Copyright (C) 2002
//# 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: casa-feedback@nrao.edu.
//# Postal address: AIPS++ Project Office
//# National Radio Astronomy Observatory
//# 520 Edgemont Road
//# Charlottesville, VA 22903-2475 USA
#ifndef FITS_FITSKEYWORDUTIL_H
#define FITS_FITSKEYWORDUTIL_H
#include <casacore/casa/aips.h>
#include <casacore/casa/Arrays/ArrayFwd.h>
namespace casacore { //# NAMESPACE CASACORE - BEGIN
class ConstFitsKeywordList;
class FitsKeywordList;
class RecordInterface;
class IPosition;
class String;
// <summary>
// A class with static functions to help deal with FITS Keywords.
// </summary>
// <use visibility=export>
// <reviewed reviewer="Eric Sessoms" date="2002/08/19" tests="tFITSKeywordUtil.cc">
// </reviewed>
// <prerequisite>
// <li> General knowledge of FITS, and particularly FITS keywords, is
// assumed.
// <li> Presumably you are using this class in conjunction
// with the "native"
// <linkto class=FitsKeywordList>FitsKeywordList</linkto>
// <li> You also need to understand the
// <linkto class=RecordInterface>RecordInterface</linkto>
// class.
// </prerequisite>
//
// <etymology>
// This is a collection of static utility functions for use with FITS
// keywords.
// </etymology>
//
// <synopsis>
// This class provides functions to conveniently interconvert between Casacore
// types and a FitsKeywordList which is needed by the native FITS classes.
// It is more convenient to maintain the list within Casacore
// as a Record, so we only need methods to turn a FitsKeywordList into a
// Record, and vice versa.
//
// Note that it is not necessary to construct a FITSKeywordUtil object
// since you can use its static functions directly.
// </synopsis>
//
// <example>
// This example shows how you put values from a Record into a
// FItsKeywordList.
// <srcblock>
// Record rec;
// rec.define("hello", 6.5);
// rec.define("world", True);
// Vector<Int> naxis(5);
// naxis(0) = 128;
// naxis(1) = 64;
// naxis(2) = 32;
// naxis(3) = 16;
// naxis(4) = 8;
// rec.define("naxis", naxis);
// // fields can have comments
// rec.setComment("hello","A comment for HELLO");
// // Add a comment to the rec
// FITSKeywordUtil::addComment(rec,"My comment goes here");
// // Create an empty FitsKeywordList, containing only "SIMPLE=T"
// FitsKeywordList kwl = FITSKeywordUtil::makeKeywordList();
// // and add the fields in rec to this list
// FITSKeywordUtil::addKeywords(kwl, rec);
// </srcblock>
// </example>
//
// <example>
// This example shows how you extract fits keywords into a Record.
// <srcblock>
// Record rec;
// FitsKeywordList kwl;
// ConstFitsKeywordList kwlRO;
// Vector<String> ignore(1);
// ignore(1)= "simple"; // ignore the SIMPLE keyword
// FITSKeywordUtil::getKeywords(rec, kwlRO, ignore);
// </srcblock>
// </example>
//
// <motivation>
// The FitsKeywordList class can be somewhat tedious to use, as it deals with,
// e.g., char* pointers rather than Strings. This class makes it easy to
// interconvert between FITS keywords and Casacore types.
// </motivation>
//
// <todo asof="2000/06/21">
// <li> Get/set history as a vector of strings as well.
// <li> This could be a namespace rather than a class.
// </todo>
class FITSKeywordUtil
{
public:
// Make an initial FitsKeywordList for either a FITS primary header
// or a FITS extension header (image or table). A primary header
// requires "SIMPLE = T", an extension header "XTENSION = IMAGE "
// or "XTENSION = BINTABLE " for image or table, respectively.
// This is required of any FITS keyword list. This is provided as
// a convenience so that you do not have to know anything about the class
// <linkto class=FitsKeywordList>FitsKeywordList</linkto>.
static FitsKeywordList makeKeywordList(Bool primHead=True, Bool binImage=True);
// Add the fields from in to the out FitsKeywordList as keywords.
// Upcases field names, turns arrays into indexed keywords, tries to interleave
// e.g. crval, crpix, etc.
// COMMENT* are standalone comments, and HISTORY* are history cards.
// (COMMENT and HISTORY may be of any capitalization). Note however that
// you will generally add History keywords with the class
// <linkto class=FITSHistoryUtil>FITSHistoryUtil</linkto>.
// Returns False in the following instances:
// <ul>
// <li> The value of a string field is longer than 68 characters. The value is truncated.
// <li> An illegal type for a FITS keyword (e.g. Complex). The field is ignored.
// <li> An array field has more than 2 dimensions. The field is stored as a vector.
// <li> An array field name is too long to hold the name and the index characters. The name is truncated.
// <li> Too many rows or columns for a 2D array (first 999 in each are used).
// <li> Too many elements in a 1D array (first 999 are used).
// <li> A field is neither a scalar or an array (e.g. a record). The field is ignored.
// </ul>
static Bool addKeywords(FitsKeywordList &out, const RecordInterface &in);
// Extract keywords from in and define them in out.
// Output field names are downcased. Keywords matching
// the names in ignore (which are treated as regular expressions) are
// not created in out. This test happens after the field names
// have been downcased.
// All indexed keywords will be ignored if the root name is in the ignore
// vector (e.g. NAXIS implies NAXIS4 and other indexed NAXIS keywords
// are ignored).
// By default history keywords are ignored, since they
// should be handled in class
// <linkto class=FITSHistoryUtil>FITSHistoryUtil</linkto>.
// This always returns True.
static Bool getKeywords(RecordInterface &out, ConstFitsKeywordList &in,
const Vector<String> &ignore,
Bool ignoreHistory=True);
// Remove some keywords from a record. This can be useful
// if, e.g., you first need to construct a coordinate system from the
// header, but you later want to remove CROTA etc.
// The strings in the ignore vector are treated as regular expressions.
static void removeKeywords(RecordInterface &out,
const Vector<String> &ignore);
// Convert a TDIMnnn keyword value into an IPosition. This returns
// False if the tdim string has an invalid format.
static Bool fromTDIM(IPosition& shape, const String& tdim);
// Convert an IPosition to a String appropriate for use as the
// value of a TDIMnnn keyword. This returns False if the
// converted string has more than 71 characters
// (making it impossible to be used as a string keyword value).
static Bool toTDIM(String& tdim, const IPosition& shape);
// Add a comment/history to the supplied record. It will automatically
// figure out a unique name and add it to the end. If the comment contains
// embedded newlines this function will break the string across multiple
// FITS comment entries. At present it will not however make sure that the
// strings are short enough (i.e. <= 72 characters per line).
//
// Note that while you can add history anywhere into header, in the actual
// keyword list they will always appear after the END keyword.
// Note however that you will generally manipulate History keywords with
// the class <linkto class=FITSHistoryUtil>FITSHistoryUtil</linkto>.
// <group>
static void addComment(RecordInterface &header, const String &comment);
static void addHistory(RecordInterface &header, const String &history);
// </group>
};
} //# NAMESPACE CASACORE - END
#endif
casacore::ConstFitsKeywordList
list of read-only FITS keywords
Definition fits.h:949
casacore::FITSKeywordUtil
Definition FITSKeywordUtil.h:126
casacore::FITSKeywordUtil::makeKeywordList
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...
casacore::FITSKeywordUtil::toTDIM
static Bool toTDIM(String &tdim, const IPosition &shape)
Convert an IPosition to a String appropriate for use as the value of a TDIMnnn keyword.
casacore::FITSKeywordUtil::fromTDIM
static Bool fromTDIM(IPosition &shape, const String &tdim)
Convert a TDIMnnn keyword value into an IPosition.
casacore::FITSKeywordUtil::addHistory
static void addHistory(RecordInterface &header, const String &history)
casacore::FITSKeywordUtil::addComment
static void addComment(RecordInterface &header, const String &comment)
Add a comment/history to the supplied record.
casacore::FITSKeywordUtil::getKeywords
static Bool getKeywords(RecordInterface &out, ConstFitsKeywordList &in, const Vector< String > &ignore, Bool ignoreHistory=True)
Extract keywords from in and define them in out.
casacore::FITSKeywordUtil::removeKeywords
static void removeKeywords(RecordInterface &out, const Vector< String > &ignore)
Remove some keywords from a record.
casacore::FITSKeywordUtil::addKeywords
static Bool addKeywords(FitsKeywordList &out, const RecordInterface &in)
Add the fields from in to the out FitsKeywordList as keywords.
casacore::FitsKeywordList
linked list of FITS keywords
Definition fits.h:735
casacore::IPosition
Definition IPosition.h:117
casacore::String
String: the storage and methods of handling collections of characters.
Definition String.h:223
casacore::Vector
Definition Vector.h:82
casacore
this file contains all the compiler specific defines
Definition mainpage.dox:28
casacore::shape
IPosition shape(const RecordFieldId &) const
Get the actual shape of this field.
casacore::comment
const String & comment(const RecordFieldId &) const override
Get the comment for this field.
casacore::RecordInterface
RecordInterface()
The default constructor creates an empty record with a variable structure.
casacore::Bool
bool Bool
Define the standard types used by Casacore.
Definition aipstype.h:40
casacore::True
const Bool True
Definition aipstype.h:41