TableSlice (tablesaw-core 0.43.1 API)

java.lang.Object
- tech.tablesaw.table.Relation
- - tech.tablesaw.table.TableSlice

All Implemented Interfaces:

Iterable<Row>
```
public class TableSlice
extends Relation
```
A TableSlice is a facade around a Relation that acts as a filter. Requests for data are forwarded to the underlying table. A TableSlice can be sorted independently of the underlying table.
A TableSlice is only good until the structure of the underlying table changes.

Constructor Summary

Constructors
Constructor	Description
`TableSlice(Table table)`	Returns a new view constructed from the given table.
`TableSlice(Table table, Selection rowSelection)`	Returns a new View constructed from the given table, containing only the rows represented by the bitmap

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`TableSlice`	`addColumns(Column<?>... column)`	Adds the given columns to this Relation and returns the same relation.
`Table`	`asTable()`	Returns the data in this slice as a new Table
`void`	`clear()`	Clears all rows from this View, leaving the structure in place
`Column<?>`	`column(int columnIndex)`	Returns the column at columnIndex (0-based)
`Column<?>`	`column(String columnName)`	Returns the column with the given columnName, ignoring case
`int`	`columnCount()`	Returns the number of columns in the relation
`int`	`columnIndex(Column<?> column)`	Returns the index of the given column
`List<String>`	`columnNames()`	Returns a list containing the names of all the columns in this relation
`List<Column<?>>`	`columns()`	Returns a list of all the columns in the relation
`Table`	`first(int nRows)`	Returns a new table containing the first n rows in this Relation
`Object`	`get(int r, int c)`	Returns the value at the given row and column indexes
`Table`	`getTable()`	Returns the backing table for this slice
`Iterator<Row>`	`iterator()`	Iterate over the underlying rows in the source table.
`int`	`mappedRowNumber(int rowNumber)`	Maps the view row number to the row number on the underlying source table.
`String`	`name()`	Returns the name of this relation
`double`	`reduce(String numberColumnName, NumericAggregateFunction function)`	Returns the result of applying the given function to the specified column
`TableSlice`	`removeColumns(Column<?>... columns)`	Removes the given columns from this Relation and returns the same relation.
`void`	`removeSelection()`	Removes the selection from this view, leaving it with the same number of rows as the underlying source table.
`void`	`removeSort()`	Removes the sort from this View.
`int`	`rowCount()`	Returns the number of rows in the relation
`TableSlice`	`setName(String name)`	Sets the name of this Relation and returns the same relation.
`void`	`sortOn(Sort key)`	Sort this view in place without modifying or copying the underlying source table.
`protected PrimitiveIterator.OfInt`	`sourceRowNumberIterator()`	IntIterator of source table row numbers that are present in this view.

Methods inherited from interface java.lang.Iterable
forEach, spliterator

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

Methods inherited from class tech.tablesaw.table.Relation
as, booleanColumn, booleanColumn, booleanColumns, categoricalColumn, categoricalColumn, categoricalColumns, columnIndex, columns, columns, columnsOfType, columnTypes, colWidths, containsColumn, containsColumn, dateColumn, dateColumn, dateColumns, dateTimeColumn, dateTimeColumn, dateTimeColumns, doubleColumn, doubleColumn, floatColumn, floatColumn, getString, getString, getUnformatted, instantColumn, instantColumn, instantColumns, intColumn, intColumn, isEmpty, longColumn, longColumn, nCol, nCol, numberColumn, numberColumn, numberColumns, numericColumns, numericColumns, numericColumns, print, print, printAll, removeColumns, removeColumns, shape, shortColumn, shortColumn, smile, stringColumn, stringColumn, stringColumns, structure, summary, textColumn, textColumn, timeColumn, timeColumn, timeColumns, toString, typeArray, types

- Constructor Detail
  - TableSlice
```
public TableSlice(Table table,
                  Selection rowSelection)
```
    Returns a new View constructed from the given table, containing only the rows represented by the bitmap
  - TableSlice
```
public TableSlice(Table table)
```
    Returns a new view constructed from the given table. The view can be sorted independently of the table.
- Method Detail
  - column
```
public Column<?> column(int columnIndex)
```
    Returns the column at columnIndex (0-based)
    
    Specified by:
    
    column in class Relation
    
    Parameters:
    
    columnIndex - an integer at least 0 and less than number of columns in the relation
    
    Returns:
    
    the column at the given index
  - column
```
public Column<?> column(String columnName)
```
    Returns the column with the given columnName, ignoring case
    
    Overrides:
    
    column in class Relation
  - columnCount
```
public int columnCount()
```
    Returns the number of columns in the relation
    
    Specified by:
    
    columnCount in class Relation
  - rowCount
```
public int rowCount()
```
    Returns the number of rows in the relation
    
    Specified by:
    
    rowCount in class Relation
  - columns
```
public List<Column<?>> columns()
```
    Returns a list of all the columns in the relation
    
    Specified by:
    
    columns in class Relation
  - columnIndex
```
public int columnIndex(Column<?> column)
```
    Returns the index of the given column
    
    Specified by:
    
    columnIndex in class Relation
  - get
```
public Object get(int r,
                  int c)
```
    Returns the value at the given row and column indexes
    
    Overrides:
    
    get in class Relation
    
    Parameters:
    
    r - the row index, 0 based
    
    c - the column index, 0 based
  - name
```
public String name()
```
    Returns the name of this relation
    
    Specified by:
    
    name in class Relation
  - getTable
```
public Table getTable()
```
    Returns the backing table for this slice
  - clear
```
public void clear()
```
    Clears all rows from this View, leaving the structure in place
    
    Specified by:
    
    clear in class Relation
  - removeSort
```
public void removeSort()
```
    Removes the sort from this View.
  - removeSelection
```
public void removeSelection()
```
    Removes the selection from this view, leaving it with the same number of rows as the underlying source table.
  - columnNames
```
public List<String> columnNames()
```
    Returns a list containing the names of all the columns in this relation
    
    Specified by:
    
    columnNames in class Relation
  - addColumns
```
public TableSlice addColumns(Column<?>... column)
```
    Adds the given columns to this Relation and returns the same relation.
    
    Specified by:
    
    addColumns in class Relation
    
    Returns:
    
    This Relation
  - removeColumns
```
public TableSlice removeColumns(Column<?>... columns)
```
    Removes the given columns from this Relation and returns the same relation.
    
    Specified by:
    
    removeColumns in class Relation
    
    Returns:
    
    This Relation
  - first
```
public Table first(int nRows)
```
    Returns a new table containing the first n rows in this Relation
    
    Specified by:
    
    first in class Relation
  - setName
```
public TableSlice setName(String name)
```
    Sets the name of this Relation and returns the same relation.
    
    Specified by:
    
    setName in class Relation
    
    Returns:
    
    This Relation
  - asTable
```
public Table asTable()
```
    Returns the data in this slice as a new Table
  - sourceRowNumberIterator
```
protected PrimitiveIterator.OfInt sourceRowNumberIterator()
```
    IntIterator of source table row numbers that are present in this view. This can be used to in combination with the source table to iterate over the cells of a column in a sorted order without copying the column.
    
    Returns:
    
    an int iterator of row numbers in the source table that are present in this view.
  - reduce
```
public double reduce(String numberColumnName,
                     NumericAggregateFunction function)
```
    Returns the result of applying the given function to the specified column
    
    Parameters:
    
    numberColumnName - The name of a numeric column in this table
    
    function - A numeric reduce function
    
    Returns:
    
    the function result
    
    Throws:
    
    IllegalArgumentException - if numberColumnName doesn't name a numeric column in this table
  - iterator
```
public Iterator<Row> iterator()
```
    Iterate over the underlying rows in the source table. If you set one of the rows while iterating it will change the row in the source table.
  - mappedRowNumber
```
public int mappedRowNumber(int rowNumber)
```
    Maps the view row number to the row number on the underlying source table.
    
    Parameters:
    
    rowNumber - the row number in the view.
    
    Returns:
    
    the matching row number in the underlying table.
  - sortOn
```
public void sortOn(Sort key)
```
    Sort this view in place without modifying or copying the underlying source table. Unlike Table.sortOn(Sort) which returns a copy of the table, this method sorts the view in place.
    
    Parameters:
    
    key - to sort on.

Class TableSlice

Constructor Summary

Method Summary

Methods inherited from interface java.lang.Iterable

Methods inherited from class java.lang.Object

Methods inherited from class tech.tablesaw.table.Relation

Constructor Detail

TableSlice

TableSlice

Method Detail

column

column

columnCount

rowCount

columns

columnIndex

get

name

getTable

clear

removeSort

removeSelection

columnNames

addColumns

removeColumns

first

setName

asTable

sourceRowNumberIterator

reduce

iterator

mappedRowNumber

sortOn