CCfits  2.4
Classes | Public Member Functions | Static Public Member Functions | Protected Member Functions
CCfits::ExtHDU Class Reference

base class for all FITS extension HDUs, i.e. Image Extensions and Tables. More...

#include <ExtHDU.h>

Inheritance diagram for CCfits::ExtHDU:
Inheritance diagram CCfits::HDU CCfits::ImageExt< T > CCfits::Table CCfits::AsciiTable CCfits::BinTable

List of all members.

Classes

class  WrongExtensionType
 Exception to be thrown on unmatched extension types. More...

Public Member Functions

 ExtHDU (const ExtHDU &right)
 copy constructor
virtual ~ExtHDU ()
 destructor
virtual void addColumn (ValueType type, const String &columnName, long repeatWidth, const String &colUnit=String(""), long decimals=-1, size_t columnNumber=0)
 add a new column to an existing table HDU.
virtual HDUclone (FITSBase *p) const =0
 virtual copy constructor
virtual Columncolumn (const String &colName, bool caseSensitive=true) const
 return a reference to a Table column specified by name.
virtual Columncolumn (int colIndex) const
 return a reference to a Table column specified by column index.
virtual const std::map< string,
Column * > & 
column () const
 return a reference to the array containing the columns.
virtual void deleteColumn (const String &columnName)
 delete a column in a Table extension by name.
virtual long getRowsize () const
 return the optimal number of rows to read or write at a time
bool isCompressed () const
 return true if image is stored using compression.
virtual void makeThisCurrent () const
 move the fitsfile pointer to this current HDU.
const String & name () const
 return the name of the extension.
virtual int numCols () const
 return the number of Columns in the Table (the TFIELDS keyword).
template<typename S >
void read (std::valarray< S > &image)
 Read image data into container.
template<typename S >
void read (std::valarray< S > &image, long first, long nElements, S *nullValue)
 read part of an image array, processing null values.
template<typename S >
void read (std::valarray< S > &image, const std::vector< long > &first, long nElements, S *nullValue)
 read part of an image array, processing null values.
template<typename S >
void read (std::valarray< S > &image, const std::vector< long > &firstVertex, const std::vector< long > &lastVertex, const std::vector< long > &stride)
 read an image subset
template<typename S >
void read (std::valarray< S > &image, long first, long nElements)
 read an image section starting at a specified pixel
template<typename S >
void read (std::valarray< S > &image, const std::vector< long > &first, long nElements)
 read an image section starting at a location specified by an n-tuple
template<typename S >
void read (std::valarray< S > &image, const std::vector< long > &firstVertex, const std::vector< long > &lastVertex, const std::vector< long > &stride, S *nullValue)
 read an image subset into valarray image, processing null values
virtual void readData (bool readFlag=false, const std::vector< String > &keys=std::vector< String >())=0
 read data from HDU depending on readFlag and keys.
virtual long rows () const
 return the number of rows in the extension.
int version () const
 return the extension version number.
void version (int value)
 set the extension version number
template<typename S >
void write (const std::vector< long > &first, long nElements, const std::valarray< S > &data, S *nullValue)
 Write a set of pixels to an image extension with the first pixel specified by an n-tuple, processing undefined data.
template<typename S >
void write (long first, long nElements, const std::valarray< S > &data, S *nullValue)
 write array to image starting with a specified pixel and allowing undefined data to be processed
template<typename S >
void write (const std::vector< long > &first, long nElements, const std::valarray< S > &data)
 write array starting from specified n-tuple, without undefined data processing
template<typename S >
void write (long first, long nElements, const std::valarray< S > &data)
 write array starting from specified pixel number, without undefined data processing
template<typename S >
void write (const std::vector< long > &firstVertex, const std::vector< long > &lastVertex, const std::valarray< S > &data)
 write a subset (generalize slice) of data to the image

Static Public Member Functions

static void readHduName (const fitsfile *fptr, int hduIndex, String &hduName, int &hduVersion)
 read extension name.

Protected Member Functions

 ExtHDU (FITSBase *p, HduType xtype, const String &hduName, int version)
 default constructor, required as Standard Library Container content.
 ExtHDU (FITSBase *p, HduType xtype, const String &hduName, int bitpix, int naxis, const std::vector< long > &axes, int version)
 writing constructor.
 ExtHDU (FITSBase *p, HduType xtype, int number)
 ExtHDU constructor for getting ExtHDUs by number.
long gcount () const
 return required gcount keyword value
void gcount (long value)
 set required gcount keyword value
long pcount () const
 return required pcount keyword value
void pcount (long value)
 set required pcount keyword value
HduType xtension () const
 return the extension type
void xtension (HduType value)
 set the extension type

Detailed Description

base class for all FITS extension HDUs, i.e. Image Extensions and Tables.

ExtHDU needs to have the combined public interface of Table objects and images. It achieves this by providing the same set of read and write operations as PHDU, and also providing the same operations for extracting columns from the extension as does Table [after which the column interface is accessible]. Differentiation between extension types operates by exception handling: .i.e. attempting to access image data structures on a Table object through the ExtHDU interface will or trying to return a Column reference from an Image extension will both throw an exception


Constructor & Destructor Documentation

CCfits::ExtHDU::ExtHDU ( FITSBase *  p,
HduType  xtype,
const String &  hduName,
int  bitpix,
int  naxis,
const std::vector< long > &  axes,
int  version 
) [protected]

writing constructor.

The writing constructor forces the user to supply a name for the HDU. The bitpix, naxes and naxis data required by this constructor are required FITS keywords for any HDUs.

CCfits::ExtHDU::ExtHDU ( FITSBase *  p,
HduType  xtype,
int  number 
) [protected]

ExtHDU constructor for getting ExtHDUs by number.

Necessary since EXTNAME is a reserved, not required, keyword. But a synthetic name is supplied by static ExtHDU::readHduName which is called by this constructor.


Member Function Documentation

void CCfits::ExtHDU::addColumn ( ValueType  type,
const String &  columnName,
long  repeatWidth,
const String &  colUnit = String(""),
long  decimals = -1,
size_t  columnNumber = 0 
) [virtual]

add a new column to an existing table HDU.

Parameters:
typeThe data type of the column to be added
columnNameThe name of the column to be added
repeatWidthfor a string valued, this is the width of a string. For a numeric column it supplies the vector length of the rows. It is ignored for ascii table numeric data.
colUnitan optional field specifying the units of the data (TUNITn)
decimalsoptional parameter specifying the number of decimals for an ascii numeric column
columnNumberoptional parameter specifying column number to be created. If not specified the column is added to the end. If specified, the column is inserted and the columns already read are reindexed. This parameter is provided as a convenience to support existing code rather than recommended.

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

Column & CCfits::ExtHDU::column ( const String &  colName,
bool  caseSensitive = true 
) const [virtual]

return a reference to a Table column specified by name.

If the caseSensitive parameter is set to false, the search will be case-insensitive. The overridden base class implementation ExtHDU::column throws an exception, which is thus the action to be taken if self is an image extension

Exceptions:
WrongExtensionTypesee above

Reimplemented in CCfits::Table.

Column & CCfits::ExtHDU::column ( int  colIndex) const [virtual]

return a reference to a Table column specified by column index.

This version is provided for convenience; the 'return by name' version is more efficient because columns are stored in an associative array sorted by name.

Exceptions:
WrongExtensionTypethrown if *this is an image extension.

Reimplemented in CCfits::Table.

const map< string, Column * > & CCfits::ExtHDU::column ( ) const [virtual]

return a reference to the array containing the columns.

Exceptions:
WrongExtensionTypethrown if *this is an image extension.

Reimplemented in CCfits::Table.

void CCfits::ExtHDU::deleteColumn ( const String &  columnName) [virtual]

delete a column in a Table extension by name.

Parameters:
columnNameThe name of the column to be deleted.
Exceptions:
WrongExtensionTypeif extension is an image.

Reimplemented in CCfits::Table.

long CCfits::ExtHDU::getRowsize ( ) const [virtual]

return the optimal number of rows to read or write at a time

A wrapper for the CFITSIO function fits_get_rowsize, useful for obtaining maximum I/O efficiency. This will throw if it is not called for a Table extension.

Reimplemented in CCfits::Table.

bool CCfits::ExtHDU::isCompressed ( ) const

return true if image is stored using compression.

This is simply a wrapper around the CFITSIO fits_is_compressed_image function. It will throw if this is not an Image extension.

void CCfits::ExtHDU::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 from CCfits::HDU.

int CCfits::ExtHDU::numCols ( ) const [virtual]

return the number of Columns in the Table (the TFIELDS keyword).

Exceptions:
WrongExtensionTypethrown if *this is an image extension.

Reimplemented in CCfits::Table.

template<typename S >
void CCfits::ExtHDU::read ( std::valarray< S > &  image)

Read image data into container.

The container image contains the entire image array after the call. This and all the other variants of read() throw a WrongExtensionType exception if called for a Table object.

template<typename S >
void CCfits::ExtHDU::read ( std::valarray< S > &  image,
long  first,
long  nElements,
S *  nullValue 
)

read part of an image array, processing null values.

Implicit data conversion is supported (i.e. user does not need to know the type of the data stored. A WrongExtensionType extension is thrown if *this is not an image.

Parameters:
imageThe receiving container, a std::valarray reference
firstThe first pixel from the array to read [a long value]
nElementsThe number of values to read
nullValueA pointer containing the value in the table to be considered as undefined. See cfitsio for details
template<typename S >
void CCfits::ExtHDU::read ( std::valarray< S > &  image,
const std::vector< long > &  first,
long  nElements,
S *  nullValue 
)

read part of an image array, processing null values.

As above except for

Parameters:
firsta vector<long> representing an n-tuple giving the coordinates in the image of the first pixel.
template<typename S >
void CCfits::ExtHDU::read ( std::valarray< S > &  image,
const std::vector< long > &  firstVertex,
const std::vector< long > &  lastVertex,
const std::vector< long > &  stride,
S *  nullValue 
)

read an image subset into valarray image, processing null values

The image subset is defined by two vertices and a stride indicating the 'denseness' of the values to be picked in each dimension (a stride = (1,1,1,...) means picking every pixel in every dimension, whereas stride = (2,2,2,...) means picking every other value in each dimension.

static void CCfits::ExtHDU::readHduName ( const fitsfile *  fptr,
int  hduIndex,
String &  hduName,
int &  hduVersion 
) [static]

read extension name.

Used primarily to allow extensions to be specified by HDU number and provide their name for the associative array that contains them. Alternatively, if there is no name keyword in the extension, one is synthesized from the index.

long CCfits::ExtHDU::rows ( ) const [virtual]

return the number of rows in the extension.

Exceptions:
WrongExtensionTypethrown if *this is an image extension.

Reimplemented in CCfits::Table.

template<typename S >
void CCfits::ExtHDU::write ( const std::vector< long > &  first,
long  nElements,
const std::valarray< S > &  data,
S *  nullValue 
)

Write a set of pixels to an image extension with the first pixel specified by an n-tuple, processing undefined data.

All the overloaded versions of ExtHDU::write perform operations on *this if it is an image and throw a WrongExtensionType exception if not. Where appropriate, alternate versions allow undefined data to be processed

Parameters:
firstan n-tuple of dimension equal to the image dimension specifying the first pixel in the range to be written
nElementsnumber of pixels to be written
dataarray of data to be written
nullValuepointer to null value (data with this value written as undefined; needs the BLANK keyword to have been specified).
template<typename S >
void CCfits::ExtHDU::write ( long  first,
long  nElements,
const std::valarray< S > &  data,
S *  nullValue 
)

write array to image starting with a specified pixel and allowing undefined data to be processed

parameters after the first are as for version with n-tuple specifying first element. these two version are equivalent, except that it is possible for the first pixel number to exceed the range of 32-bit integers, which is how long datatype is commonly implemented.

template<typename S >
void CCfits::ExtHDU::write ( const std::vector< long > &  firstVertex,
const std::vector< long > &  lastVertex,
const std::valarray< S > &  data 
)

write a subset (generalize slice) of data to the image

A generalized slice/subset is a subset of the image (e.g. one plane of a data cube of size <= the dimension of the cube). It is specified by two opposite vertices. The equivalent cfitsio call does not support undefined data processing so there is no version that allows a null value to be specified.

Parameters:
firstVertexthe coordinates specifying lower and upper vertices of the n-dimensional slice
lastVertex
dataThe data to be written
HduType CCfits::ExtHDU::xtension ( ) const [inline, protected]

return the extension type

allowed values are ImageHDU, AsciiTbl, and BinaryTbl


The documentation for this class was generated from the following files: