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CCfits::HDU Class Reference

Base class for all HDU [Header-Data Unit] objects. More...

#include <HDU.h>

Inheritance diagram for CCfits::HDU::

Inheritance diagram
CCfits::ExtHDU CCfits::PHDU CCfits::Table CCfits::AsciiTable CCfits::BinTable List of all members.

Public Methods

 HDU (const HDU &right)
bool operator== (const HDU &right) const
bool operator!= (const HDU &right) const
virtual HDU* clone (FITSBase *p) const=0
fitsfile* fitsPointer () const
virtual void makeThisCurrent () const
std::map<string, Keyword*> keyWord ()
KeywordkeyWord (const string &keyName)
const string& getHistory ()
const string& getComments ()
void writeHistory (const string &history="Generic History String")
void writeComment (const string &comment="Generic Comment")
void writeDate ()
FITSBase* parent () const
void readAllKeys ()
long axes () const
long axis (size_t index) const
void index (int value)
void deleteKey (const std::string &doomed)
long bitpix () const
void bitpix (long value)
int index () const
const string& history () const
const string& comment () const
virtual double zero () const
virtual double scale () const
const std::map<string,Keyword*>& keyWord () const
const KeywordkeyWord (const string &keyname) const
void setKeyWord (const string &keyname, Keyword &value)
template<typename T> KeywordaddKey (const string &name, T val, const string &comment)
template<typename T> void readKey (const string &keyName, T &val)
template<typename T> void readKeys (std::vector< string > &keyNames, std::vector< T > &vals)

Protected Methods

 HDU (FITSBase *p=0)
 HDU (FITSBase *p, int bitpix, int naxis, const std::vector< long > &axes)
virtual ~HDU ()
std::vector< long >& naxes ()

Detailed Description

Base class for all HDU [Header-Data Unit] objects.

HDU objects in CCfits are either PHDU (Primary HDU objects) or ExtHDU (Extension HDU) objects. Following the behavior. ExtHDUs are further subclassed into ImageExt or Table objects, which are finally AsciiTable or BinTable objects.

HDU's public interface gives access to properties that are common to all HDUs, largely required keywords, and functions that are common to all HDUs, principally the manipulation of keywords and their values.

HDUs must be constructed by HDUCreator objects which are called by FITS methods. Each HDU has an embedded pointer to a FITSBase object, which is private to FITS [FITSBase is a pointer encapsulating the resources of FITS. For details of this coding idiom see Exceptional C++ by Herb Sutter (2000) and references therein].


Constructor & Destructor Documentation

CCfits::HDU::HDU ( const HDU & right )
 

copy constructor.

CCfits::HDU::HDU ( FITSBase * p = 0 ) [protected]
 

default constructor, called by HDU subclasses that read from FITS files.

CCfits::HDU::HDU ( FITSBase * p,
int bitpix,
int naxis,
const std::vector< long > & axes ) [protected]
 

constructor for creating new HDU objects, called by HDU subclasses writing to FITS files.

CCfits::HDU::~HDU ( ) [protected, virtual]
 

destructor.


Member Function Documentation

template<typename T>
Keyword & CCfits::HDU::addKey ( const string & name,
T value,
const string & comment )
 

create a new keyword in the HDU with specified value and comment fields.

the function returns a reference to keyword object just created.

Parameters:

Parameters:
name   (std::string) The keyword name
value   (T = std::string, float, std::complex<float>, int, or bool
comment   (std::string) the keyword value

Note the limitations on T, which arise for historical reasons (i.e. since keywords do not contain explicit type information, routines in CCfits must assign a type). The limitation may be removed in a future release

It is possible however to create a keyword of any of the allowed data types in fitsio (see the cfitsio manual section 4.3). The required calls are, e.g. for a floating point double valued keyword:

NewKeyword<double> keyCreate( hdu, double val1 ); Keyword* key1 = Keyword keyCreate.MakeKeyword(keyName1, const string& comment); keyCreate.keyData(val2); Keyword* key2 = Keyword keyCreate.MakeKeyword(keyName2, const string& comment);

key1->write(); key2->write();

... which is essentially what addKey does for its allowed types.

long CCfits::HDU::axes ( ) const [inline]
 

return the number of axes in the HDU data section (always 2 for tables).

long CCfits::HDU::axis ( size_t index ) const [inline]
 

return the length of HDU data axis i.

void CCfits::HDU::bitpix ( long value ) [inline]
 

set the data type keyword.

long CCfits::HDU::bitpix ( ) const [inline]
 

return the data type keyword.

Takes values denoting the image data type for images, and takes the fixed value 8 for tables.

HDU * CCfits::HDU::clone ( FITSBase * p ) const [pure virtual]
 

virtual copy constructor, to be implemented in subclasses.

Reimplemented in CCfits::AsciiTable, CCfits::BinTable, CCfits::ExtHDU, and CCfits::PHDU.

const string & CCfits::HDU::comment ( ) const [inline]
 

return the comment string previously read by getComment().

void CCfits::HDU::deleteKey ( const std::string & doomed )
 

delete a keyword from the header.

removes doomed from the FITS file and from the FITS object

fitsfile * CCfits::HDU::fitsPointer ( ) const
 

return the fitsfile pointer for the FITS object containing the HDU.

const string & CCfits::HDU::getComments ( )
 

read the comments from the HDU and add it to the FITS object.

The comment string found in the header is concatenated and returned to the calling function

const string & CCfits::HDU::getHistory ( )
 

read the history information from the HDU and add it to the FITS object.

The history string found in the header is concatenated and returned to the calling function

const string & CCfits::HDU::history ( ) const [inline]
 

return the history string previously read by getHistory().

int CCfits::HDU::index ( ) const [inline]
 

return the HDU number.

void CCfits::HDU::index ( int value ) [inline]
 

set the HDU number.

const Keyword & CCfits::HDU::keyWord ( const string & keyname ) const [inline]
 

return a (previously read) keyword from the HDU object. const version.

const std::map< string, Keyword *> & CCfits::HDU::keyWord ( ) const [inline]
 

return the associative array containing the HDU Keywords that have been read so far.

Keyword & CCfits::HDU::keyWord ( const string & keyName ) [inline]
 

return a (previously read) keyword from the HDU object.

std::map< string, Keyword *> CCfits::HDU::keyWord ( ) [inline]
 

return the associative array containing the HDU keywords so far read.

void CCfits::HDU::makeThisCurrent ( ) const [virtual]
 

move the fitsfile pointer to this current HDU.

This function should never need to be called by the user since it is called internally whenever required.

Reimplemented in CCfits::ExtHDU.

std::vector< long > & CCfits::HDU::naxes ( ) [inline, protected]
 

return the HDU data axis array.

bool CCfits::HDU::operator!= ( const HDU & right ) const
 

inequality operator.

bool CCfits::HDU::operator== ( const HDU & right ) const
 

equality operator.

FITSBase * CCfits::HDU::parent ( ) const
 

return reference to the pointer representing the FITSBase object containing the HDU.

void CCfits::HDU::readAllKeys ( )
 

read all of the keys in the header.

This member function reads keys that are not meta data for columns or image information, [which are considered to be part of the column or image objects]. Also, history and comment keys are read and returned by getHistory() and getComment().

Note that readAllKeys can only construct keys of type string, float, complex<float>, integer, and bool because the FITS header records do not encode exact type information.

template<typename T>
void CCfits::HDU::readKey ( const string & keyName,
T & val )
 

read a keyword of specified type from the header of a disk FITS file and return its value.

T is one of the types std::string, float, int, std::complex<float>, and bool.

template<typename T>
void CCfits::HDU::readKeys ( std::vector< string > & keyNames,
std::vector< T > & vals )
 

read a set of specified keywords of the same data type from the header of a disk FITS file and return their values.

T is one of the types std::string, float, int, std::complex<float>, and bool.

double CCfits::HDU::scale ( ) const [inline, virtual]
 

return the BSCALE keyword value.

Reimplemented in CCfits::PHDU.

void CCfits::HDU::setKeyWord ( const string & keyname,
Keyword & value ) [inline]
 

set Keyword keyname to specified value.

void CCfits::HDU::writeComment ( const string & comment = "Generic Comment" )
 

write a comment string.

A default value for the string is given ("Generic Comment String") so users can put a placeholder call to this function in their code.

void CCfits::HDU::writeDate ( )
 

write a date string to *this.

void CCfits::HDU::writeHistory ( const string & history = "Generic History String" )
 

write a history string.

A default value for the string is given ("Generic History String") so users can put a placeholder call to this function in their code.

double CCfits::HDU::zero ( ) const [inline, virtual]
 

return the BZERO keyword value.

Reimplemented in CCfits::PHDU.


The documentation for this class was generated from the following files:
Generated at Fri Apr 11 16:05:11 2003 for CCfits by doxygen1.2.7 written by Dimitri van Heesch, © 1997-2001