Constructor Detail

• JELTable

  public JELTable(uk.ac.starlink.table.StarTable baseTable,
                  uk.ac.starlink.table.ColumnInfo[] colInfos,
                  java.lang.String[] exprs)
           throws gnu.jel.CompilationException

  Constructor. The number of columns is the same as the number of elements of colInfos, which must be the same as the number of elements in exprs. If the contentClass attributes of the colInfos elements are non-null, they must be compatible with the actual types of the evaluated expressions. If they are not, an IllegalArgumentException will be thrown.

  Parameters:

  baseTable - table which provides both behaviour determining whether random access is available etc, and an evaluation context for the JEL calculations

  colInfos - column metadata for each of the columns in this table

  exprs - JEL expressions, evaluated in a context determined by baseTable, which give the data for this table.

  Throws:

  gnu.jel.CompilationException

Method Detail

• getColumnCount

  public int getColumnCount()

  Specified by:

  getColumnCount in interface uk.ac.starlink.table.StarTable

  Overrides:

  getColumnCount in class uk.ac.starlink.table.WrapperStarTable

• getColumnInfo

  public uk.ac.starlink.table.ColumnInfo getColumnInfo(int icol)

  Specified by:

  getColumnInfo in interface uk.ac.starlink.table.StarTable

  Overrides:

  getColumnInfo in class uk.ac.starlink.table.WrapperStarTable

• getCell

  public java.lang.Object getCell(long irow,
                                  int icol)
                           throws java.io.IOException

  Specified by:

  getCell in interface uk.ac.starlink.table.StarTable

  Overrides:

  getCell in class uk.ac.starlink.table.WrapperStarTable

  Throws:

  java.io.IOException

• getRow

  public java.lang.Object[] getRow(long irow)
                            throws java.io.IOException

  Specified by:

  getRow in interface uk.ac.starlink.table.StarTable

  Overrides:

  getRow in class uk.ac.starlink.table.WrapperStarTable

  Throws:

  java.io.IOException

• getRowSequence

  public uk.ac.starlink.table.RowSequence getRowSequence()
                                                  throws java.io.IOException

  Specified by:

  getRowSequence in interface uk.ac.starlink.table.StarTable

  Overrides:

  getRowSequence in class uk.ac.starlink.table.WrapperStarTable

  Throws:

  java.io.IOException

• createJELTable

  public static uk.ac.starlink.table.StarTable createJELTable(uk.ac.starlink.table.StarTable baseTable,
                                                              uk.ac.starlink.table.ValueInfo[] infos,
                                                              java.lang.String[] exprs)
                                                       throws uk.ac.starlink.task.ExecutionException

  Convenience factory method. It turns all the supplied infos into ColumnInfos and rethrows any CompilationException as an ExecutionException.

  Parameters:

  baseTable - table which provides both behaviour determining whether random access is available etc, and an evaluation context for the JEL calculations

  infos - metadata used to construct column metadata

  exprs - JEL expressions, evaluated in a context determined by baseTable, which give the data for this table

  Returns:

  new table

  Throws:

  uk.ac.starlink.task.ExecutionException

• createJELTable

  public static uk.ac.starlink.table.StarTable createJELTable(uk.ac.starlink.table.StarTable baseTable,
                                                              java.lang.String[] exprs)
                                                       throws gnu.jel.CompilationException

  Creates a JELTable from a base table and a list of column expressions. If the expressions can be determined to correspond to columns from the base table, the metadata is propagated. Otherwise, column names are constructed from the expression strings.

  Parameters:

  baseTable - table which provides both behaviour determining whether random access is available etc, and an evaluation context for the JEL calculations

  exprs - JEL expressions, evaluated in a context determined by baseTable, which give the data for this table

  Returns:

  new table

  Throws:

  gnu.jel.CompilationException