ConstantColumnData (Starjava TOPCAT API)

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

Fields
Modifier and Type	Field	Description
`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

Constructors
Constructor Description

ConstantColumnData(java.lang.String name, double value)
Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`equals(java.lang.Object other)`
`int`	`hashCode()`
`java.lang.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(java.lang.String name,
                          double value)
```
    Constructor.
    
    Parameters:
    
    name - column name
    
    value - constant column value
- Method Detail
  - readValue
```
public java.lang.Object readValue(long irow)
```
    Specified by:
    
    readValue in class uk.ac.starlink.table.ColumnData
  - equals
```
public boolean equals(java.lang.Object other)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object