uk.ac.starlink.topcat.plot
Class ConstantColumnData

java.lang.Object
  uk.ac.starlink.table.ColumnData
      uk.ac.starlink.topcat.plot.ConstantColumnData

public class ConstantColumnData
extends uk.ac.starlink.table.ColumnData

ColumnData implementation which always returns the same Double value. The equals and hashCode methods are implemented so that instances with the same values are equal to each other.

Since:

1 Jun 2007

Author:

Mark Taylor

Field Summary

static ConstantColumnData	NAN Instance with values of Double.NaN.
static ConstantColumnData	ONE Instance with values of 1.
static ConstantColumnData	ZERO Instance with values of 0.

Constructor Summary

ConstantColumnData(String name, double value)
Constructor.

Method Summary

boolean	equals(Object other)
int	hashCode()
Object	readValue(long irow)

Methods inherited from class uk.ac.starlink.table.ColumnData

getColumnInfo, isWritable, setColumnInfo, storeValue

Methods inherited from class java.lang.Object

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

Field Detail

ZERO

public static final ConstantColumnData ZERO

Instance with values of 0.

ONE

public static final ConstantColumnData ONE

Instance with values of 1.

NAN

public static final ConstantColumnData NAN

Instance with values of Double.NaN.

Constructor Detail

ConstantColumnData

public ConstantColumnData(String name,
                          double value)

Constructor.

Parameters:

name - column name

value - constant column value

Method Detail

readValue

public Object readValue(long irow)

Specified by:

readValue in class uk.ac.starlink.table.ColumnData

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object