Package uk.ac.starlink.ttools.plottask
Class TablePointSequence
java.lang.Object
uk.ac.starlink.ttools.plottask.TablePointSequence
- All Implemented Interfaces:
PointSequence
PointSequence abstract superclass implementation for getting sequential
plot data from a table.
- Since:
- 13 Aug 2008
- Author:
- Mark Taylor
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Constructor Summary
ConstructorsModifierConstructorDescriptionprotected
TablePointSequence
(SequentialJELRowReader rseq, String labelExpr, String[] setExprs) Constructor. -
Method Summary
Modifier and TypeMethodDescriptionvoid
close()
Call when this sequence is no longer required.protected Object
evaluate
(gnu.jel.CompiledExpression compex) Convenience method which evaluates an Object-valued compiled expression.protected double
evaluateDouble
(gnu.jel.CompiledExpression compex) Convenience method which evaluates a numeric-valued compiled expression.getLabel()
Returns any text label associated with the current point.boolean
isIncluded
(int iset) Indicates whether the current row is included in the given subset.boolean
next()
Attempts to advance the current row to the next one.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.PointSequence
getErrors, getPoint
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Constructor Details
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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 datalabelExpr
- 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
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Method Details
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next
public boolean next()Description copied from interface:PointSequence
Attempts to advance the current row to the next one. Iftrue
is returned the attempt has been successful, and iffalse
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 interfacePointSequence
- Returns:
- true if row advance has succeeded, false for end of sequence
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getLabel
Description copied from interface:PointSequence
Returns any text label associated with the current point.- Specified by:
getLabel
in interfacePointSequence
- Returns:
- text label, or null
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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 interfacePointSequence
- Returns:
- true iff set
iset
is included
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close
public void close()Description copied from interface:PointSequence
Call when this sequence is no longer required.- Specified by:
close
in interfacePointSequence
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evaluate
Convenience method which evaluates an Object-valued compiled expression. Any resulting exceptions are rethrown as PlotDataExceptions.- Parameters:
compex
- compiled expression- Returns:
- expression value
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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
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