uk.ac.starlink.ttools.filter

Class KeepColumnFilter

java.lang.Object

uk.ac.starlink.ttools.filter.BasicFilter

uk.ac.starlink.ttools.filter.KeepColumnFilter

All Implemented Interfaces:

ProcessingFilter

public class KeepColumnFilter
extends BasicFilter

Table filter for selecting a number of columns and discarding the rest.

Since:

3 Mar 2005

Author:

Mark Taylor (Starlink)

Constructor Summary

Constructors

Constructor and Description
KeepColumnFilter()

Method Summary

Modifier and Type	Method and Description
ProcessingStep	createStep(Iterator<String> argIt) Creates a new ProcessingStep based on a sequence of command-line arguments.
protected String[]	getDescriptionLines()
static StarTable	keepColumnTable(StarTable table, String colIdList) Returns a table which selects a number of columns from its base table by column ID.

Methods inherited from class uk.ac.starlink.ttools.filter.BasicFilter

explainSyntax, getDescription, getName, getUsage

Methods inherited from class java.lang.Object

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

Constructor Detail

KeepColumnFilter

public KeepColumnFilter()

Method Detail

getDescriptionLines

protected String[] getDescriptionLines()

Specified by:

getDescriptionLines in class BasicFilter

createStep

public ProcessingStep createStep(Iterator<String> argIt)
                          throws ArgException

Description copied from interface: ProcessingFilter

Creates a new ProcessingStep based on a sequence of command-line arguments. The argIt argument is an iterator over the command-line arguments positioned just before any arguments intended for this filter. If legal, any that can be comprehended by this filter should be read (iterated over) and removed, and a ProcessingStep should accordingly be returned. In the case of a successful return, it is essential that no arguments other than the ones intended for this filter are read from the iterator.

If the argument list is badly-formed as far as this filter is concerned, an ArgException should be thrown.

Parameters:

argIt - iterator over command-line arguments positioned at the first one

Throws:

ArgException

keepColumnTable

public static StarTable keepColumnTable(StarTable table,
                                        String colIdList)
                                 throws IOException

Returns a table which selects a number of columns from its base table by column ID.

Parameters:

table - base table

colIdList - list of column IDs, one for each column in the output table

Returns:

new table using columns selected from table

Throws:

IOException