org.datavec.dataframe.table

Class TemporaryView

java.lang.Object

org.datavec.dataframe.table.TemporaryView

All Implemented Interfaces:

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

public class TemporaryView
extends java.lang.Object
implements Relation, 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
void	addColumn(Column... column)
Table	asTable()
BooleanColumn	booleanColumn(int columnIndex)
BooleanColumn	booleanColumn(java.lang.String columnName)
CategoryColumn	categoryColumn(int columnIndex)
CategoryColumn	categoryColumn(java.lang.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
java.util.List<java.lang.String>	columnNames()
java.util.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(java.lang.String columnName)
DateTimeColumn	dateTimeColumn(int columnIndex)
DateTimeColumn	dateTimeColumn(java.lang.String columnName)
Table	first(int nRows)
FloatColumn	floatColumn(int columnIndex)
FloatColumn	floatColumn(java.lang.String columnName)
java.lang.String	get(int c, int r) Returns a String representing the value found at column index c and row index r
IntColumn	intColumn(int columnIndex)
IntColumn	intColumn(java.lang.String columnName)
it.unimi.dsi.fastutil.ints.IntIterator	iterator()
LongColumn	longColumn(int columnIndex)
LongColumn	longColumn(java.lang.String columnName)
java.lang.String	name() Returns the name of this relation
NumericColumn	numericColumn(int columnIndex)
NumericColumn	numericColumn(java.lang.String columnName)
java.lang.String	print()
double	reduce(java.lang.String numericColumnName, NumericReduceFunction function) Returns the result of applying the given function to the specified column
void	removeColumns(Column... columns) Removes the given columns from the receiver
int	rowCount() Returns the number of rows in the relation
void	setName(java.lang.String name)
ShortColumn	shortColumn(int columnIndex)
ShortColumn	shortColumn(java.lang.String columnName)
TimeColumn	timeColumn(int columnIndex)
TimeColumn	timeColumn(java.lang.String columnName)
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.datavec.dataframe.table.Relation

column, columnIndex, columnTypes, isEmpty, nCol, nCol, removeColumn, removeColumns, shape, structure, summary

Methods inherited from interface java.lang.Iterable

forEach, 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 interface: Relation

Returns the column at columnIndex (0-based)

Specified by:

column in interface 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 interface: Relation

Returns the number of columns in the relation

Specified by:

columnCount in interface Relation

rowCount

public int rowCount()

Description copied from interface: Relation

Returns the number of rows in the relation

Specified by:

rowCount in interface Relation

columns

public java.util.List<Column> columns()

Description copied from interface: Relation

Returns a list of all the columns in the relation

Specified by:

columns in interface Relation

columnIndex

public int columnIndex(Column column)

Description copied from interface: Relation

Returns the index of the given column

Specified by:

columnIndex in interface Relation

get

public java.lang.String get(int c,
                            int r)

Description copied from interface: Relation

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

Specified by:

get in interface Relation

addColumn

public void addColumn(Column... column)

Specified by:

addColumn in interface Relation

name

public java.lang.String name()

Description copied from interface: Relation

Returns the name of this relation

Specified by:

name in interface Relation

clear

public void clear()

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

Specified by:

clear in interface Relation

columnNames

public java.util.List<java.lang.String> columnNames()

Specified by:

columnNames in interface Relation

removeColumns

public void removeColumns(Column... columns)

Description copied from interface: Relation

Removes the given columns from the receiver

Specified by:

removeColumns in interface Relation

first

public Table first(int nRows)

Specified by:

first in interface Relation

setName

public void setName(java.lang.String name)

Specified by:

setName in interface Relation

print

public java.lang.String print()

Specified by:

print in interface Relation

colWidths

public int[] colWidths()

Returns an array of column widths for printing tables

Specified by:

colWidths in interface Relation

asTable

public Table asTable()

reduce

public double reduce(java.lang.String numericColumnName,
                     NumericReduceFunction 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:

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

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

booleanColumn

public BooleanColumn booleanColumn(int columnIndex)

Specified by:

booleanColumn in interface Relation

booleanColumn

public BooleanColumn booleanColumn(java.lang.String columnName)

Specified by:

booleanColumn in interface Relation

floatColumn

public FloatColumn floatColumn(int columnIndex)

Specified by:

floatColumn in interface Relation

floatColumn

public FloatColumn floatColumn(java.lang.String columnName)

Specified by:

floatColumn in interface Relation

intColumn

public IntColumn intColumn(java.lang.String columnName)

Specified by:

intColumn in interface Relation

intColumn

public IntColumn intColumn(int columnIndex)

Specified by:

intColumn in interface Relation

shortColumn

public ShortColumn shortColumn(java.lang.String columnName)

Specified by:

shortColumn in interface Relation

shortColumn

public ShortColumn shortColumn(int columnIndex)

Specified by:

shortColumn in interface Relation

longColumn

public LongColumn longColumn(java.lang.String columnName)

Specified by:

longColumn in interface Relation

longColumn

public LongColumn longColumn(int columnIndex)

Specified by:

longColumn in interface Relation

dateColumn

public DateColumn dateColumn(int columnIndex)

Specified by:

dateColumn in interface Relation

dateColumn

public DateColumn dateColumn(java.lang.String columnName)

Specified by:

dateColumn in interface Relation

timeColumn

public TimeColumn timeColumn(java.lang.String columnName)

Specified by:

timeColumn in interface Relation

timeColumn

public TimeColumn timeColumn(int columnIndex)

Specified by:

timeColumn in interface Relation

dateTimeColumn

public DateTimeColumn dateTimeColumn(int columnIndex)

Specified by:

dateTimeColumn in interface Relation

dateTimeColumn

public DateTimeColumn dateTimeColumn(java.lang.String columnName)

Specified by:

dateTimeColumn in interface Relation

categoryColumn

public CategoryColumn categoryColumn(java.lang.String columnName)

Specified by:

categoryColumn in interface Relation

categoryColumn

public CategoryColumn categoryColumn(int columnIndex)

Specified by:

categoryColumn in interface Relation

numericColumn

public NumericColumn numericColumn(int columnIndex)

Specified by:

numericColumn in interface Relation

numericColumn

public NumericColumn numericColumn(java.lang.String columnName)

Specified by:

numericColumn in interface 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 java.lang.Iterable<java.lang.Integer>