uk.ac.starlink.ttools.plottask

Class TablePlotData

java.lang.Object

uk.ac.starlink.ttools.plottask.TablePlotData

All Implemented Interfaces:

PlotData

Direct Known Subclasses:

CartesianTablePlotData

public abstract class TablePlotData
extends Object
implements PlotData

Abstract superclass for PlotData implementation representing the data from a single table with associated expressions describing coordinate selections etc. Concrete subclasses must see to provision of coordinate and error data.

Since:

22 Apr 2008

Author:

Mark Taylor

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TablePlotData(StarTable table, String[] setExprs, String[] setNames, Style[] setStyles, String labelExpr) Constructor.

Method Summary

Modifier and Type	Method and Description
void	checkExpressions() Checks that any JEL expressions used by the data for this object compile correctly.
protected abstract PointSequence	createPointSequence(SequentialJELRowReader rseq) Constructs a point sequence suitable for dispensing by this plot data.
PointSequence	getPointSequence() Returns an iterator over the data points in this object.
int	getSetCount() Returns the number of subsets in this object.
String	getSetName(int iset) Returns the name for a given subset.
Style	getSetStyle(int iset) Returns the plotting style for a given subset.
boolean	hasLabels() Indicates whether there are or may be text labels associated with the data points in this object.

Methods inherited from class java.lang.Object

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

Methods inherited from interface uk.ac.starlink.ttools.plot.PlotData

getNdim, getNerror

Constructor Detail

TablePlotData

protected TablePlotData(StarTable table,
                        String[] setExprs,
                        String[] setNames,
                        Style[] setStyles,
                        String labelExpr)

Constructor.

Parameters:

table - table this data is based on

setExprs - nset-element array of JEL boolean expressions for subset inclusion criteria

setNames - nset-element array of subset names

setStyles - nset-element array of subset plot styles

labelExpr - JEL String expression for text label

Method Detail

createPointSequence

protected abstract PointSequence createPointSequence(SequentialJELRowReader rseq)
                                              throws gnu.jel.CompilationException

Constructs a point sequence suitable for dispensing by this plot data.

Parameters:

rseq - row reader representing this data's table

Returns:

new point sequence for plotting

Throws:

gnu.jel.CompilationException

getSetCount

public int getSetCount()

Description copied from interface: PlotData

Returns the number of subsets in this object.

Specified by:

getSetCount in interface PlotData

Returns:

subset count

getSetName

public String getSetName(int iset)

Description copied from interface: PlotData

Returns the name for a given subset.

Specified by:

getSetName in interface PlotData

Parameters:

iset - subset index

Returns:

subset name

getSetStyle

public Style getSetStyle(int iset)

Description copied from interface: PlotData

Returns the plotting style for a given subset.

Specified by:

getSetStyle in interface PlotData

Parameters:

iset - subset index

Returns:

subset style

hasLabels

public boolean hasLabels()

Description copied from interface: PlotData

Indicates whether there are or may be text labels associated with the data points in this object.

Specified by:

hasLabels in interface PlotData

Returns:

true if PointSequence.getLabel() may have non-null returns

getPointSequence

public PointSequence getPointSequence()

Description copied from interface: PlotData

Returns an iterator over the data points in this object.

Specified by:

getPointSequence in interface PlotData

Returns:

new point iterator

checkExpressions

public void checkExpressions()
                      throws gnu.jel.CompilationException

Checks that any JEL expressions used by the data for this object compile correctly. A dummy call of createPointSequence(uk.ac.starlink.ttools.jel.SequentialJELRowReader) is made.

Throws:

gnu.jel.CompilationException - if one is thrown by createPointSequence