tech.tablesaw.table

Class TemporaryView

java.lang.Object

tech.tablesaw.table.Relation

tech.tablesaw.table.TemporaryView

All Implemented Interfaces:

it.unimi.dsi.fastutil.ints.IntIterable, Iterable<Integer>

public class TemporaryView
extends Relation
implements it.unimi.dsi.fastutil.ints.IntIterable

A TemporaryView is a facade around a Relation that acts as a filtering. Requests for data are forwarded to the underlying table.

The view is only good until the structure of the underlying table changes, after which it is marked 'stale'. At that point, it's operations will return an error.

View is something of a misnomer, as it is not like a database view, which is merely a query masquerading as a table, nor is it like a materialized database view, which is like a real table.

Constructor Summary

Constructors

Constructor and Description
TemporaryView(Table table, Selection rowSelection) Returns a new View constructed from the given table, containing only the rows represented by the bitmap

Method Summary

Modifier and Type	Method and Description
TemporaryView	addColumn(Column... column)
Table	asTable()
BooleanColumn	booleanColumn(int columnIndex)
BooleanColumn	booleanColumn(String columnName)
CategoryColumn	categoryColumn(int columnIndex)
CategoryColumn	categoryColumn(String columnName)
void	clear() Clears all rows from this View, leaving the structure in place
Column	column(int columnIndex) Returns the column at columnIndex (0-based)
int	columnCount() Returns the number of columns in the relation
int	columnIndex(Column column) Returns the index of the given column
List<String>	columnNames()
List<Column>	columns() Returns a list of all the columns in the relation
int[]	colWidths() Returns an array of column widths for printing tables
DateColumn	dateColumn(int columnIndex)
DateColumn	dateColumn(String columnName)
DateTimeColumn	dateTimeColumn(int columnIndex)
DateTimeColumn	dateTimeColumn(String columnName)
Table	first(int nRows)
FloatColumn	floatColumn(int columnIndex)
FloatColumn	floatColumn(String columnName)
String	get(int r, int c) Returns a String representing the value found at column index c and row index r
IntColumn	intColumn(int columnIndex)
IntColumn	intColumn(String columnName)
it.unimi.dsi.fastutil.ints.IntIterator	iterator()
LongColumn	longColumn(int columnIndex)
LongColumn	longColumn(String columnName)
String	name() Returns the name of this relation
NumericColumn	numericColumn(int columnIndex)
NumericColumn	numericColumn(String columnName)
String	print()
double	reduce(String numericColumnName, AggregateFunction function) Returns the result of applying the given function to the specified column
TemporaryView	removeColumns(Column... columns) Removes the given columns from the receiver
int	rowCount() Returns the number of rows in the relation
TemporaryView	setName(String name)
ShortColumn	shortColumn(int columnIndex)
ShortColumn	shortColumn(String columnName)
TimeColumn	timeColumn(int columnIndex)
TimeColumn	timeColumn(String columnName)

Methods inherited from class tech.tablesaw.table.Relation

asColumnMatrix, asMatrix, column, columnIndex, columnTypes, doubleColumn, doubleColumn, isEmpty, nCol, nCol, print, removeColumn, removeColumns, shape, structure, summary, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface it.unimi.dsi.fastutil.ints.IntIterable

forEach, forEach

Methods inherited from interface java.lang.Iterable

spliterator

Constructor Detail

TemporaryView

public TemporaryView(Table table,
                     Selection rowSelection)

Returns a new View constructed from the given table, containing only the rows represented by the bitmap

Method Detail

column

public Column column(int columnIndex)

Description copied from class: Relation

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

columnCount

public int columnCount()

Description copied from class: Relation

Returns the number of columns in the relation

Specified by:

columnCount in class Relation

rowCount

public int rowCount()

Description copied from class: Relation

Returns the number of rows in the relation

Specified by:

rowCount in class Relation

columns

public List<Column> columns()

Description copied from class: Relation

Returns a list of all the columns in the relation

Specified by:

columns in class Relation

columnIndex

public int columnIndex(Column column)

Description copied from class: Relation

Returns the index of the given column

Specified by:

columnIndex in class Relation

get

public String get(int r,
                  int c)

Description copied from class: Relation

Returns a String representing the value found at column index c and row index r

Specified by:

get in class Relation

addColumn

public TemporaryView addColumn(Column... column)

Specified by:

addColumn in class Relation

name

public String name()

Description copied from class: Relation

Returns the name of this relation

Specified by:

name in class Relation

clear

public void clear()

Clears all rows from this View, leaving the structure in place

Specified by:

clear in class Relation

columnNames

public List<String> columnNames()

Specified by:

columnNames in class Relation

removeColumns

public TemporaryView removeColumns(Column... columns)

Description copied from class: Relation

Removes the given columns from the receiver

Specified by:

removeColumns in class Relation

first

public Table first(int nRows)

Specified by:

first in class Relation

setName

public TemporaryView setName(String name)

Specified by:

setName in class Relation

print

public String print()

Overrides:

print in class Relation

colWidths

public int[] colWidths()

Returns an array of column widths for printing tables

Overrides:

colWidths in class Relation

asTable

public Table asTable()

reduce

public double reduce(String numericColumnName,
                     AggregateFunction function)

Returns the result of applying the given function to the specified column

Parameters:

numericColumnName - The name of a numeric (integer, float, etc.) column in this table

function - A numeric reduce function

Returns:

the function result

Throws:

IllegalArgumentException - if numericColumnName doesn't name a numeric column in this table

booleanColumn

public BooleanColumn booleanColumn(int columnIndex)

Overrides:

booleanColumn in class Relation

booleanColumn

public BooleanColumn booleanColumn(String columnName)

Overrides:

booleanColumn in class Relation

floatColumn

public FloatColumn floatColumn(int columnIndex)

Overrides:

floatColumn in class Relation

floatColumn

public FloatColumn floatColumn(String columnName)

Overrides:

floatColumn in class Relation

intColumn

public IntColumn intColumn(String columnName)

Overrides:

intColumn in class Relation

intColumn

public IntColumn intColumn(int columnIndex)

Overrides:

intColumn in class Relation

shortColumn

public ShortColumn shortColumn(String columnName)

Overrides:

shortColumn in class Relation

shortColumn

public ShortColumn shortColumn(int columnIndex)

Overrides:

shortColumn in class Relation

longColumn

public LongColumn longColumn(String columnName)

Overrides:

longColumn in class Relation

longColumn

public LongColumn longColumn(int columnIndex)

Overrides:

longColumn in class Relation

dateColumn

public DateColumn dateColumn(int columnIndex)

Overrides:

dateColumn in class Relation

dateColumn

public DateColumn dateColumn(String columnName)

Overrides:

dateColumn in class Relation

timeColumn

public TimeColumn timeColumn(String columnName)

Overrides:

timeColumn in class Relation

timeColumn

public TimeColumn timeColumn(int columnIndex)

Overrides:

timeColumn in class Relation

dateTimeColumn

public DateTimeColumn dateTimeColumn(int columnIndex)

Overrides:

dateTimeColumn in class Relation

dateTimeColumn

public DateTimeColumn dateTimeColumn(String columnName)

Overrides:

dateTimeColumn in class Relation

categoryColumn

public CategoryColumn categoryColumn(String columnName)

Overrides:

categoryColumn in class Relation

categoryColumn

public CategoryColumn categoryColumn(int columnIndex)

Overrides:

categoryColumn in class Relation

numericColumn

public NumericColumn numericColumn(int columnIndex)

Overrides:

numericColumn in class Relation

numericColumn

public NumericColumn numericColumn(String columnName)

Overrides:

numericColumn in class Relation

iterator

public it.unimi.dsi.fastutil.ints.IntIterator iterator()

Specified by:

iterator in interface it.unimi.dsi.fastutil.ints.IntIterable

Specified by:

iterator in interface Iterable<Integer>