Class NullDataHDU

java.lang.Object

nom.tam.fits.BasicHDU<ImageData>

nom.tam.fits.ImageHDU

nom.tam.fits.NullDataHDU

All Implemented Interfaces:

FitsElement

public class NullDataHDU
extends ImageHDU

A class of HDU that contains only a header only with no associated data. Such HDUs are commonly used as the primary HDU in FITS files where the leading data is not an image, since only images may constitute the primary HDU.

Since:

1.18

Author:

Attila Kovacs

See Also:

• NullData

Field Summary

Fields inherited from class BasicHDU

BITPIX_BYTE, BITPIX_DOUBLE, BITPIX_FLOAT, BITPIX_INT, BITPIX_LONG, BITPIX_SHORT

Modifier and Type	Field	Description
static final int	BITPIX_BYTE	Deprecated. Use Bitpix.VALUE_FOR_BYTE instead.
static final int	BITPIX_DOUBLE	Deprecated. Use Bitpix.VALUE_FOR_DOUBLE instead.
static final int	BITPIX_FLOAT	Deprecated. Use Bitpix.VALUE_FOR_FLOAT instead.
static final int	BITPIX_INT	Deprecated. Use Bitpix.VALUE_FOR_INT instead.
static final int	BITPIX_LONG	Deprecated. Use Bitpix.VALUE_FOR_LONG instead.
static final int	BITPIX_SHORT	Deprecated. Use Bitpix.VALUE_FOR_SHORT instead.

Constructor Summary

Constructors

Constructor	Description
NullDataHDU()	Instantiates a new HDU with a default header and no associated data.
NullDataHDU(Header myHeader)	Instantiates a new HDU with only the supplied header and no associated data.

Method Summary

Modifier and Type	Method	Description
NullData	getData()	Returns the data component of this HDU.
void	info(PrintStream stream)	Print out some information about this HDU.

Methods inherited from class ImageHDU

encapsulate, getBlankValue, getBScale, getBUnit, getBZero, getTiler, isData, isHeader, manufactureData, manufactureHeader

Modifier and Type	Method	Description
static ImageData	encapsulate(Object o)	Deprecated. (for internal use) Use ImageData.from(Object) instead.
long	getBlankValue()	Returns the integer value that signifies blank (missing or null) data in an integer image.
double	getBScale()	Returns the floating-point increment between adjacent integer values in the image.
String	getBUnit()	Returns the name of the physical unit in which images are represented.
double	getBZero()	Returns the floating-point value that corresponds to an 0 integer value in the image.
StandardImageTiler	getTiler()	Returns the class that can be used to divide this image into tiles that may be processed separately (and in parallel).
static boolean	isData(Object o)	Deprecated. (for internal use) Will reduce visibility in the future
static boolean	isHeader(Header hdr)	Deprecated. (for internal use) Will reduce visibility in the future
static ImageData	manufactureData(Header hdr)	Deprecated. (for internal use) Will reduce visibility in the future
static Header	manufactureHeader(Data d)	Deprecated. (for internal use) Will reduce visibility in the future

Methods inherited from class BasicHDU

addValue, addValue, addValue, addValue, addValue, addValue, addValue, addValue, calcChecksum, card, getAuthor, getAxes, getBitpix, getBitPix, getCreationDate, getDummyHDU, getEpoch, getEquinox, getFileOffset, getGroupCount, getHeader, getInstrument, getKernel, getMaximumValue, getMinimumValue, getObject, getObservationDate, getObserver, getOrigin, getParameterCount, getReference, getSize, getStoredChecksum, getStoredDatasum, getTelescope, getTrimmedString, getTrimmedString, read, reset, rewrite, rewriteable, setChecksum, verifyDataIntegrity, verifyIntegrity, write

Modifier and Type	Method	Description
void	addValue(String key, boolean val, String comment)	Add information to the header.
void	addValue(String key, double val, String comment)	Add information to the header.
void	addValue(String key, int val, String comment)	Add information to the header.
void	addValue(String key, String val, String comment)	Add information to the header.
void	addValue(IFitsHeader key, boolean val)	Add information to the header.
void	addValue(IFitsHeader key, double val)	Add information to the header.
void	addValue(IFitsHeader key, int val)	Add information to the header.
void	addValue(IFitsHeader key, String val)	Add information to the header.
long	calcChecksum()	Deprecated. Use BasicHDU.verifyIntegrity() instead when appropriate.
HeaderCardBuilder	card(IFitsHeader key)	Returns a header card builder for filling the header cards using the builder pattern.
String	getAuthor()	Return the name of the person who compiled the information in the data associated with this header.
int[]	getAxes()	In FITS files the index represented by NAXIS1 is the index that changes most rapidly.
Bitpix	getBitpix()	Return the Bitpix enum type for this HDU.
final int	getBitPix()	Deprecated. (for internal use) Will reduce visibility or remove entirely in the future.
Date	getCreationDate()	Get the FITS file creation date as a Date object.
static NullDataHDU	getDummyHDU()	Deprecated. Use NullDataHDU instead.
double	getEpoch()	Deprecated. use BasicHDU.getEquinox() instead
double	getEquinox()	Get the equinox in years for the celestial coordinate system in which positions given in either the header or data are expressed.
long	getFileOffset()	Returns the byte offset at which this element starts ina file.
int	getGroupCount()	Deprecated. Should not be exposed outside of RandomGroupsHDU -- will reduce visibility in the future/
Header	getHeader()	Returns the FITS header component of this HDU
String	getInstrument()	Get the name of the instrument which was used to acquire the data in this FITS file.
final Object	getKernel()	Returns the underlying Java object (usually an array of some type) that stores the data internally.
double	getMaximumValue()	Return the minimum valid value in the array.
double	getMinimumValue()	Return the minimum valid value in the array.
String	getObject()	Get the name of the observed object in this FITS file.
Date	getObservationDate()	Get the FITS file observation date as a Date object.
String	getObserver()	Get the name of the person who acquired the data in this FITS file.
String	getOrigin()	Get the name of the organization which created this FITS file.
int	getParameterCount()	Deprecated. Should not be exposed outside of RandomGroupsHDU -- will reduce visibility in the future.
String	getReference()	Return the citation of a reference where the data associated with this header are published.
long	getSize()	Returns the size of this elements in the FITS representation.
long	getStoredChecksum()	Deprecated. Not very useful, since it has no meaning other than ensuring that the checksum of the HDU yields (int) -1 (that is 0xffffffff) after including this value for the CHECKSUM keyword in the header.
long	getStoredDatasum()	Returns the FITS checksum for the HDU's data that is stored in the header of this HDU under the DATASUM keyword.
String	getTelescope()	Get the name of the telescope which was used to acquire the data in this FITS file.
String	getTrimmedString(String keyword)	Deprecated. (for internal use) Will reduced visibility in the future.
String	getTrimmedString(IFitsHeader keyword)	Deprecated. (for internal use) Will reduced visibility in the future.
void	read(ArrayDataInput stream)	Read a FITS element from the input, starting at the current position.
boolean	reset()	Reset the input stream to point to the beginning of this element
void	rewrite()	Rewrite the contents of the element in place.
boolean	rewriteable()	Checks if we can write this element back to its source.
void	setChecksum()	Computes the checksums for this HDU and stores the CHECKSUM and DATASUM values in the header.
boolean	verifyDataIntegrity()	Checks that the HDUs data checksum is correct.
boolean	verifyIntegrity()	Checks the HDU's integrity, using the recorded CHECKSUM and/or DATASUM keywords if present.
void	write(ArrayDataOutput stream)	Writes the contents of the element to a data sink, adding padding as necessary if the element (such as a header or data segment) is expected to complete the FITS block of 2880 bytes.

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

NullDataHDU

public NullDataHDU()

Instantiates a new HDU with a default header and no associated data.

NullDataHDU

public NullDataHDU(Header myHeader)

Instantiates a new HDU with only the supplied header and no associated data.

Parameters:

myHeader - the FITS header for this HDU

Method Details

getData

public NullData getData()

Description copied from class: BasicHDU

Returns the data component of this HDU.

Overrides:

getData in class BasicHDU<ImageData>

Returns:

the associated Data object

info

public void info(PrintStream stream)

Description copied from class: BasicHDU

Print out some information about this HDU.

Overrides:

info in class ImageHDU

Parameters:

stream - the printstream to write the info on