Class TablePointSequence

java.lang.Object
uk.ac.starlink.ttools.plottask.TablePointSequence
All Implemented Interfaces:
PointSequence

public abstract class TablePointSequence extends Object implements PointSequence
PointSequence abstract superclass implementation for getting sequential plot data from a table.
Since:
13 Aug 2008
Author:
Mark Taylor
  • Constructor Details

    • TablePointSequence

      protected TablePointSequence(SequentialJELRowReader rseq, String labelExpr, String[] setExprs) throws gnu.jel.CompilationException
      Constructor.
      Parameters:
      rseq - row sequence representing the table which contains the actual data
      labelExpr - JEL expression for text labellling each point; may be null for no label; may have any type (converted to string before use)
      setExprs - nset-element array of boolean-valued JEL expressions giving per-set point inclusion status
      Throws:
      gnu.jel.CompilationException
  • Method Details

    • next

      public boolean next()
      Description copied from interface: PointSequence
      Attempts to advance the current row to the next one. If true is returned the attempt has been successful, and if false is returned there are no more rows in this sequence. Since the initial position of this sequence is before the first row, this method must be called before calling any of the data access methods.
      Specified by:
      next in interface PointSequence
      Returns:
      true if row advance has succeeded, false for end of sequence
    • getLabel

      public String getLabel()
      Description copied from interface: PointSequence
      Returns any text label associated with the current point.
      Specified by:
      getLabel in interface PointSequence
      Returns:
      text label, or null
    • isIncluded

      public boolean isIncluded(int iset)
      Description copied from interface: PointSequence
      Indicates whether the current row is included in the given subset.
      Specified by:
      isIncluded in interface PointSequence
      Returns:
      true iff set iset is included
    • close

      public void close()
      Description copied from interface: PointSequence
      Call when this sequence is no longer required.
      Specified by:
      close in interface PointSequence
    • evaluate

      protected Object evaluate(gnu.jel.CompiledExpression compex)
      Convenience method which evaluates an Object-valued compiled expression. Any resulting exceptions are rethrown as PlotDataExceptions.
      Parameters:
      compex - compiled expression
      Returns:
      expression value
    • evaluateDouble

      protected double evaluateDouble(gnu.jel.CompiledExpression compex)
      Convenience method which evaluates a numeric-valued compiled expression. Any resulting exceptions are rethrown as PlotDataExceptions.
      Parameters:
      compex - compiled expression
      Returns:
      expression value