nom.tam.fits
Class AsciiTable

java.lang.Object
  nom.tam.fits.Data
      nom.tam.fits.AsciiTable

All Implemented Interfaces:

FitsElement, TableData

public class AsciiTable
extends Data
implements TableData

This class represents the data in an ASCII table

Field Summary

Fields inherited from class nom.tam.fits.Data

dataSize, fileOffset, input

Constructor Summary

AsciiTable()
Create an empty ASCII table

AsciiTable(Header hdr)
Create an ASCII table given a header

Method Summary

int	addColumn(java.lang.Object newCol) Add a column to the table.
int	addColumn(java.lang.Object newCol, int length) This version of addColumn allows the user to override the default length associated with each column type.
int	addRow(java.lang.Object[] newRow) Add a row to the FITS table.
void	deleteColumns(int start, int len) Delete columns from the table.
void	deleteRows(int start, int len) Delete rows from a FITS table
void	fillHeader(Header hdr) Fill in a header with information that points to this data.
java.lang.Object	getColumn(int col) Get a column of data
java.lang.Object	getData() Get the ASCII table information.
java.lang.Object	getElement(int row, int col) Get a single element as a one-d array.
int	getNCols() Get the number of columns in the table
int	getNRows() Get the number of rows in the table
java.lang.Object[]	getRow(int row) Get a row.
int	getRowLen() Get the number of bytes in a row
protected long	getTrueSize() Return the size of the data section
boolean	isNull(int row, int col) See if an element is null.
void	read(ArrayDataInput str) Read in an ASCII table.
void	setColumn(int col, java.lang.Object newData) Replace a column with new data.
void	setElement(int row, int col, java.lang.Object newData) Modify an element in the table
void	setNull(int row, int col, boolean flag) Mark (or unmark) an element as null.
void	setRow(int row, java.lang.Object[] newData) Modify a row in the table
void	updateAfterDelete(int oldNCol, Header hdr) This is called after we delete columns.
void	write(ArrayDataOutput str) Write the data to an output stream.

Methods inherited from class nom.tam.fits.Data

getFileOffset, getKernel, getSize, reset, rewrite, rewriteable, setFileOffset

Methods inherited from class java.lang.Object

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

Constructor Detail

AsciiTable

public AsciiTable(Header hdr)
           throws FitsException

Create an ASCII table given a header

Parameters:

hdr - The header describing the table

Throws:

FitsException

AsciiTable

public AsciiTable()

Create an empty ASCII table

Method Detail

read

public void read(ArrayDataInput str)
          throws FitsException

Read in an ASCII table. Reading is deferred if we are reading from a random access device

Specified by:

read in interface FitsElement

Specified by:

read in class Data

Parameters:

str -

Throws:

FitsException

getData

public java.lang.Object getData()
                         throws FitsException

Get the ASCII table information. This will actually do the read if it had previously been deferred

Specified by:

getData in class Data

Returns:

The table data as an Object[] array.

Throws:

FitsException

getColumn

public java.lang.Object getColumn(int col)
                           throws FitsException

Get a column of data

Specified by:

getColumn in interface TableData

Parameters:

col - The 0-indexed column to be returned.

Returns:

The column object -- typically as a 1-d array.

Throws:

FitsException

getRow

public java.lang.Object[] getRow(int row)
                          throws FitsException

Get a row. If the data has not yet been read just read this row.

Specified by:

getRow in interface TableData

Parameters:

row - The 0-indexed row to be returned.

Returns:

A row of data.

Throws:

FitsException

getElement

public java.lang.Object getElement(int row,
                                   int col)
                            throws FitsException

Get a single element as a one-d array. We return String's as arrays for consistency though they could be returned as a scalar.

Specified by:

getElement in interface TableData

Parameters:

row - The 0-based row

col - The 0-based column

Returns:

The requested cell data.

Throws:

FitsException - when unable to get the data.

write

public void write(ArrayDataOutput str)
           throws FitsException

Write the data to an output stream.

Specified by:

write in interface FitsElement

Specified by:

write in class Data

Parameters:

str - The output stream to be written to

Throws:

FitsException - if any IO exception is found or some inconsistency the FITS file arises.

setColumn

public void setColumn(int col,
                      java.lang.Object newData)
               throws FitsException

Replace a column with new data.

Specified by:

setColumn in interface TableData

Parameters:

col - The 0-based index to the column

newData - The column data. This is typically a 1-d array.

Throws:

FitsException

setRow

public void setRow(int row,
                   java.lang.Object[] newData)
            throws FitsException

Modify a row in the table

Specified by:

setRow in interface TableData

Parameters:

row - The 0-based index of the row

newData - The new data. Each element of this array is typically a primitive[1] array.

Throws:

FitsException

setElement

public void setElement(int row,
                       int col,
                       java.lang.Object newData)
                throws FitsException

Modify an element in the table

Specified by:

setElement in interface TableData

Parameters:

row - the 0-based row

col - the 0-based column

newData - The new value for the column. Typically a primitive[1] array.

Throws:

FitsException

setNull

public void setNull(int row,
                    int col,
                    boolean flag)

Mark (or unmark) an element as null. Note that if this FITS file is latter written out, a TNULL keyword needs to be defined in the corresponding header. This routine does not add an element for String columns.

Parameters:

row - The 0-based row.

col - The 0-based column.

flag - True if the element is to be set to null.

isNull

public boolean isNull(int row,
                      int col)

See if an element is null.

Parameters:

row - The 0-based row

col - The 0-based column

Returns:

if the given element has been nulled.

addColumn

public int addColumn(java.lang.Object newCol)
              throws FitsException

Add a column to the table. Users should be cautious of calling this routine directly rather than the corresponding routine in AsciiTableHDU since this routine knows nothing of the FITS header modifications required.

Specified by:

addColumn in interface TableData

Parameters:

newCol - the new column information. This is typically a primitive[n] or String[n] array.

Returns:

the number of fields in the table

Throws:

FitsException

addColumn

public int addColumn(java.lang.Object newCol,
                     int length)
              throws FitsException

This version of addColumn allows the user to override the default length associated with each column type.

Parameters:

newCol - The new column data

length - the requested length for the column

Returns:

the number of columns after this one is added.

Throws:

FitsException

addRow

public int addRow(java.lang.Object[] newRow)
           throws FitsException

Add a row to the FITS table.

Specified by:

addRow in interface TableData

Parameters:

newRow - The new row data.

Returns:

The number of rows after this is added.

Throws:

FitsException

deleteRows

public void deleteRows(int start,
                       int len)
                throws FitsException

Delete rows from a FITS table

Specified by:

deleteRows in interface TableData

Parameters:

start - The first (0-indexed) row to be deleted.

len - The number of rows to be deleted.

Throws:

FitsException

getTrueSize

protected long getTrueSize()

Return the size of the data section

Returns:

The size in bytes of the data section, not includeing the padding.

fillHeader

public void fillHeader(Header hdr)

Fill in a header with information that points to this data.

Parameters:

hdr - The header to be updated with information appropriate to the current table data.

getNRows

public int getNRows()

Get the number of rows in the table

Specified by:

getNRows in interface TableData

Returns:

The number of rows.

getNCols

public int getNCols()

Get the number of columns in the table

Specified by:

getNCols in interface TableData

Returns:

The number of columns

getRowLen

public int getRowLen()

Get the number of bytes in a row

Returns:

The number of bytes for a single row in the table.

deleteColumns

public void deleteColumns(int start,
                          int len)
                   throws FitsException

Delete columns from the table.

Specified by:

deleteColumns in interface TableData

Parameters:

start - The first, 0-indexed, column to be deleted.

len - The number of columns to be deleted.

Throws:

FitsException

updateAfterDelete

public void updateAfterDelete(int oldNCol,
                              Header hdr)
                       throws FitsException

This is called after we delete columns. The HDU doesn't know how to update the TBCOL entries.

Specified by:

updateAfterDelete in interface TableData

Parameters:

oldNCol - The number of columns we had before deletion.

hdr - The associated header.

Throws:

FitsException