Package uk.ac.starlink.ttools.filter

Class 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 Detail

      • KeepColumnFilter

        public KeepColumnFilter()

    • Method Detail

      • createStep

        public ProcessingStep createStep​(java.util.Iterator<java.lang.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 uk.ac.starlink.table.StarTable keepColumnTable​(uk.ac.starlink.table.StarTable table,
                                                             java.lang.String colIdList)
                                                      throws java.io.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:
        java.io.IOException