Package uk.ac.starlink.votable
Class ColFitsPlusTableBuilder
java.lang.Object
uk.ac.starlink.votable.ColFitsPlusTableBuilder
- All Implemented Interfaces:
uk.ac.starlink.table.TableBuilder
Implementation of the
TableBuilder
interface which reads
tables stored in column-oriented FITS binary table format.
The table data is stored in a BINTABLE extension which has a single row;
each cell in this row contains the data for an entire column of the
represented table. The primary HDU contains a byte[] array giving
the table metadata as a VOTable, as for FitsPlusTableBuilder
.
If the VOTMETA card in the primary HDU does not have the value T,
the VOTable metadata array is ignored.
This rather specialised format may provide good performance for certain operations on very large, especially very wide, tables. Although it is FITS and can therefore be used in principle for data interchange, in practice most non-STIL processors are unlikely to be able to do much useful with it.
- Since:
- 26 Jun 2006
- Author:
- Mark Taylor
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Constructor Summary
ConstructorsConstructorDescriptionDefault constructor.ColFitsPlusTableBuilder
(uk.ac.starlink.fits.WideFits wide) Constructor. -
Method Summary
Modifier and TypeMethodDescriptionboolean
canImport
(DataFlavor flavor) static boolean
isMagic
(byte[] buffer) Tests whether a given buffer contains bytes which might be the first few bytes of a FitsPlus table.boolean
looksLikeFile
(String location) uk.ac.starlink.table.StarTable
makeStarTable
(uk.ac.starlink.util.DataSource datsrc, boolean wantRandom, uk.ac.starlink.table.StoragePolicy policy) void
streamStarTable
(InputStream in, uk.ac.starlink.table.TableSink sink, String pos)
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Constructor Details
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ColFitsPlusTableBuilder
public ColFitsPlusTableBuilder()Default constructor. -
ColFitsPlusTableBuilder
public ColFitsPlusTableBuilder(uk.ac.starlink.fits.WideFits wide) Constructor.- Parameters:
wide
- convention for representing extended columns; use null to avoid use of extended columns
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Method Details
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getFormatName
- Specified by:
getFormatName
in interfaceuk.ac.starlink.table.TableBuilder
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looksLikeFile
- Specified by:
looksLikeFile
in interfaceuk.ac.starlink.table.TableBuilder
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streamStarTable
public void streamStarTable(InputStream in, uk.ac.starlink.table.TableSink sink, String pos) throws uk.ac.starlink.table.TableFormatException - Specified by:
streamStarTable
in interfaceuk.ac.starlink.table.TableBuilder
- Throws:
uk.ac.starlink.table.TableFormatException
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canImport
- Specified by:
canImport
in interfaceuk.ac.starlink.table.TableBuilder
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makeStarTable
public uk.ac.starlink.table.StarTable makeStarTable(uk.ac.starlink.util.DataSource datsrc, boolean wantRandom, uk.ac.starlink.table.StoragePolicy policy) throws IOException - Specified by:
makeStarTable
in interfaceuk.ac.starlink.table.TableBuilder
- Throws:
IOException
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isMagic
public static boolean isMagic(byte[] buffer) Tests whether a given buffer contains bytes which might be the first few bytes of a FitsPlus table. The criterion is that it looks like the start of a FITS header, and the first few cards look roughly like this:SIMPLE = T BITPIX = 8 NAXIS = 1 NAXIS1 = ??? COLFITS = T VOTMETA = T
- Parameters:
buffer
- byte buffer containing leading few bytes of data- Returns:
- true if it looks like a FitsPlus file
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