CalculatorColumnSupplement (Starjava TTOOLS API)

java.lang.Object
- uk.ac.starlink.ttools.filter.CalculatorColumnSupplement

All Implemented Interfaces:

ColumnSupplement
```
public abstract class CalculatorColumnSupplement
extends java.lang.Object
implements ColumnSupplement
```
ColumnSupplement whose columns are derived by calculating values based on all the columns of another table. To generate any of the columns of this table, a whole row of the input supplement must be read. Concrete implementations of this abstract class must implement the calculate(java.lang.Object[]) method.

Since:

2 Apr 2012

Author:

Mark Taylor

Constructor Summary

Constructors
Constructor Description

CalculatorColumnSupplement(ColumnSupplement baseSup, uk.ac.starlink.table.ColumnInfo[] outColInfos)
Constructor.

Constructors
Constructor	Description
`CalculatorColumnSupplement(ColumnSupplement baseSup, uk.ac.starlink.table.ColumnInfo[] outColInfos)`	Constructor.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`protected abstract java.lang.Object[]`	`calculate(java.lang.Object[] inRow)`	Performs the calculations which populate the columns of this table.
`SupplementSequence`	`createSequence(uk.ac.starlink.table.RowSequence rseq)`	Returns a new iterator over the values in the columns defined by this object.
`java.lang.Object`	`getCell(long irow, int icol)`	Random access read of a cell defined by this object.
`int`	`getColumnCount()`	Returns the number of columns defined by this object.
`uk.ac.starlink.table.ColumnInfo`	`getColumnInfo(int icol)`	Returns the column metadata object for a given column.
`static double`	`getDouble(java.lang.Object value)`	Utility method to turn an Object into a floating point value.
`java.lang.Object[]`	`getRow(long irow)`	Random access read of a row defined by this object.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - CalculatorColumnSupplement
```
public CalculatorColumnSupplement(ColumnSupplement baseSup,
                                  uk.ac.starlink.table.ColumnInfo[] outColInfos)
```
    Constructor.
    
    Parameters:
    
    baseSup - base supplement
    
    outColInfos - column metadata for the supplementary columns (length defines column count)
- Method Detail
  - calculate
```
protected abstract java.lang.Object[] calculate(java.lang.Object[] inRow)
                                         throws java.io.IOException
```
    Performs the calculations which populate the columns of this table. The input is a row of the base table, and the output is the row of this table.
    The implementation must return a new array each time, not repopulate the same Object[] array object.
    
    Parameters:
    
    inRow - input column values
    
    Returns:
    
    output column values (same size as column count)
    
    Throws:
    
    java.io.IOException
  - getColumnCount
```
public int getColumnCount()
```
    Description copied from interface: ColumnSupplement
    
    Returns the number of columns defined by this object.
    
    Specified by:
    
    getColumnCount in interface ColumnSupplement
    
    Returns:
    
    number of columns
  - getColumnInfo
```
public uk.ac.starlink.table.ColumnInfo getColumnInfo(int icol)
```
    Description copied from interface: ColumnSupplement
    
    Returns the column metadata object for a given column.
    
    Specified by:
    
    getColumnInfo in interface ColumnSupplement
    
    Parameters:
    
    icol - column index within this object
    
    Returns:
    
    column metadata for the icol'th column defined by this object
  - getRow
```
public java.lang.Object[] getRow(long irow)
                          throws java.io.IOException
```
    Description copied from interface: ColumnSupplement
    
    Random access read of a row defined by this object.
    
    Specified by:
    
    getRow in interface ColumnSupplement
    
    Parameters:
    
    irow - row index
    
    Returns:
    
    array of cell contents for all the cells in this row
    
    Throws:
    
    java.io.IOException
  - getCell
```
public java.lang.Object getCell(long irow,
                                int icol)
                         throws java.io.IOException
```
    Description copied from interface: ColumnSupplement
    
    Random access read of a cell defined by this object.
    
    Specified by:
    
    getCell in interface ColumnSupplement
    
    Parameters:
    
    irow - row index
    
    icol - column index
    
    Returns:
    
    cell content
    
    Throws:
    
    java.io.IOException
  - createSequence
```
public SupplementSequence createSequence(uk.ac.starlink.table.RowSequence rseq)
                                  throws java.io.IOException
```
    Description copied from interface: ColumnSupplement
    
    Returns a new iterator over the values in the columns defined by this object. The supplied row sequence must be from an appropriate host table; if not, behaviour is undefined.
    
    Specified by:
    
    createSequence in interface ColumnSupplement
    
    Parameters:
    
    rseq - row sequence providing data from the host table
    
    Returns:
    
    iterator over row data from supplementary columns
    
    Throws:
    
    java.io.IOException
  - getDouble
```
public static double getDouble(java.lang.Object value)
```
    Utility method to turn an Object into a floating point value. If the submitted value is not a Number (including if it is null), NaN will be returned.
    
    Parameters:
    
    value - object value
    
    Returns:
    
    floating point value

Class CalculatorColumnSupplement

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

CalculatorColumnSupplement

Method Detail

calculate

getColumnCount

getColumnInfo

getRow

getCell

createSequence

getDouble