Package tech.tablesaw.columns.strings

Class TextualStringData

java.lang.Object

tech.tablesaw.columns.strings.TextualStringData

All Implemented Interfaces:

Iterable<String>, StringData, StringFilters, StringReduceUtils, FilterSpec<Selection>, StringFilterSpec<Selection>

public class TextualStringData
extends Object
implements StringData

A column that contains String values. They are assumed to be free-form text. For categorical data, use stringColumn

This is the default column type for SQL longvarchar and longnvarchar types

Because the MISSING_VALUE for this column type is an empty string, there is little or no need for special handling of missing values in this class's methods.

Field Summary

Fields

Modifier and Type	Field	Description
protected List<String>	values

Method Summary

Modifier and Type	Method	Description
TextualStringData	addAll(List<String> stringValues)	Add all the strings in the list to this column
TextualStringData	append(String value)	Added for naming consistency with all other columns
void	append(Column<String> column)
TextualStringData	appendMissing()
TextualStringData	appendObj(Object obj)
byte[]	asBytes(int rowNumber)	Returns the contents of the cell at rowNumber as a byte[]
double[]	asDoubleArray()
List<String>	asList()	Returns a List<String> representation of all the values in this column
String[]	asObjectArray()
Set<String>	asSet()
void	clear()
boolean	contains(String aString)	Returns true if this column contains a cell with the given string, and false otherwise
TextualStringData	copy()
Table	countByCategory(String columnName)
int	countMissing()	Returns the count of missing values in this column
int	countOccurrences(String value)
int	countUnique()
static TextualStringData	create()
static TextualStringData	create(int size)
static TextualStringData	create(String... strings)
static TextualStringData	create(Collection<String> strings)
static TextualStringData	create(Stream<String> stream)
TextualStringData	emptyCopy()
TextualStringData	emptyCopy(int rowSize)
boolean	equals(int rowNumber1, int rowNumber2)
int	firstIndexOf(String value)
String	get(int rowIndex)	Returns the value at rowIndex in this column.
DictionaryMap	getDictionary()	Returns null, as this Column is not backed by a dictionaryMap
double	getDouble(int i)	Returns a double that can stand in for the string at index i in some ML applications
List<BooleanColumn>	getDummies()	Unsupported Operation This can't be used on a text column as the number of BooleanColumns would likely be excessive
boolean	isEmpty()
Selection	isIn(String... strings)
Selection	isIn(Collection<String> strings)
boolean	isMissing(int rowNumber)
Selection	isNotIn(String... strings)
Selection	isNotIn(Collection<String> strings)
Iterator<String>	iterator()
TextualStringData	lag(int n)
TextualStringData	lead(int n)
TextualStringData	removeMissing()
it.unimi.dsi.fastutil.ints.IntComparator	rowComparator()
TextualStringData	set(int rowIndex, String stringValue)
TextualStringData	set(Selection rowSelection, String newValue)	Conditionally update this column, replacing current values with newValue for all rows where the current value matches the selection criteria
TextualStringData	setMissing(int i)
int	size()	Returns the number of elements (a.k.a.
void	sortAscending()
void	sortDescending()
Table	summary()
TextualStringData	unique()	Returns a new Column containing all the unique values in this column
int	valueHash(int rowNumber)
static boolean	valueIsMissing(String string)
TextualStringData	where(Selection selection)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface tech.tablesaw.columns.strings.StringData

subset

Methods inherited from interface tech.tablesaw.columns.strings.StringFilters

containsString, endsWith, equalsIgnoreCase, equalsIgnoreCase, eval, eval, eval, eval, isAlpha, isAlphaNumeric, isEmptyString, isEqualTo, isEqualTo, isIn, isLongerThan, isLowerCase, isMissing, isNotEqualTo, isNotEqualTo, isNotIn, isNotMissing, isNumeric, isShorterThan, isUpperCase, lengthEquals, matchesRegex, startsWith, startsWith

Methods inherited from interface tech.tablesaw.columns.strings.StringReduceUtils

appendAll, appendAll

Field Detail

values

protected List<String> values

Method Detail

valueHash

public int valueHash(int rowNumber)

equals

public boolean equals(int rowNumber1,
                      int rowNumber2)

valueIsMissing

public static boolean valueIsMissing(String string)

appendMissing

public TextualStringData appendMissing()

Specified by:

appendMissing in interface StringData

create

public static TextualStringData create()

create

public static TextualStringData create(String... strings)

create

public static TextualStringData create(Collection<String> strings)

create

public static TextualStringData create(int size)

create

public static TextualStringData create(Stream<String> stream)

isMissing

public boolean isMissing(int rowNumber)

Specified by:

isMissing in interface StringData

emptyCopy

public TextualStringData emptyCopy()

Specified by:

emptyCopy in interface StringData

emptyCopy

public TextualStringData emptyCopy(int rowSize)

Specified by:

emptyCopy in interface StringData

sortAscending

public void sortAscending()

Specified by:

sortAscending in interface StringData

sortDescending

public void sortDescending()

Specified by:

sortDescending in interface StringData

size

public int size()

Returns the number of elements (a.k.a. rows or cells) in the column

Specified by:

size in interface StringFilters

Specified by:

size in interface StringReduceUtils

Returns:

size as int

get

public String get(int rowIndex)

Returns the value at rowIndex in this column. The index is zero-based.

Specified by:

get in interface StringFilters

Parameters:

rowIndex - index of the row

Returns:

value as String

Throws:

IndexOutOfBoundsException - if the given rowIndex is not in the column

asList

public List<String> asList()

Returns a List<String> representation of all the values in this column

NOTE: Unless you really need a string consider using the column itself for large datasets as it uses much less memory

Specified by:

asList in interface StringData

Returns:

values as a list of String.

countByCategory

public Table countByCategory(String columnName)

Specified by:

countByCategory in interface StringData

summary

public Table summary()

clear

public void clear()

Specified by:

clear in interface StringData

lead

public TextualStringData lead(int n)

Specified by:

lead in interface StringData

lag

public TextualStringData lag(int n)

Specified by:

lag in interface StringData

set

public TextualStringData set(Selection rowSelection,
                             String newValue)

Conditionally update this column, replacing current values with newValue for all rows where the current value matches the selection criteria

Examples: myCatColumn.set(myCatColumn.isEqualTo("Cat"), "Dog"); // no more cats myCatColumn.set(myCatColumn.valueIsMissing(), "Fox"); // no more missing values

Specified by:

set in interface StringData

set

public TextualStringData set(int rowIndex,
                             String stringValue)

Specified by:

set in interface StringData

countUnique

public int countUnique()

Specified by:

countUnique in interface StringData

contains

public boolean contains(String aString)

Returns true if this column contains a cell with the given string, and false otherwise

Specified by:

contains in interface StringData

Parameters:

aString - the value to look for

Returns:

true if contains, false otherwise

setMissing

public TextualStringData setMissing(int i)

Specified by:

setMissing in interface StringData

addAll

public TextualStringData addAll(List<String> stringValues)

Add all the strings in the list to this column

Parameters:

stringValues - a list of values

rowComparator

public it.unimi.dsi.fastutil.ints.IntComparator rowComparator()

Specified by:

rowComparator in interface StringData

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface StringData

unique

public TextualStringData unique()

Returns a new Column containing all the unique values in this column

Specified by:

unique in interface StringData

Returns:

a column with unique values.

where

public TextualStringData where(Selection selection)

Specified by:

where in interface StringData

copy

public TextualStringData copy()

Specified by:

copy in interface StringData

append

public void append(Column<String> column)

Specified by:

append in interface StringData

countMissing

public int countMissing()

Returns the count of missing values in this column

Specified by:

countMissing in interface StringData

removeMissing

public TextualStringData removeMissing()

Specified by:

removeMissing in interface StringData

iterator

public Iterator<String> iterator()

Specified by:

iterator in interface Iterable<String>

asSet

public Set<String> asSet()

Specified by:

asSet in interface StringData

asBytes

public byte[] asBytes(int rowNumber)

Returns the contents of the cell at rowNumber as a byte[]

Specified by:

asBytes in interface StringData

append

public TextualStringData append(String value)

Added for naming consistency with all other columns

Specified by:

append in interface StringData

appendObj

public TextualStringData appendObj(Object obj)

Specified by:

appendObj in interface StringData

isIn

public Selection isIn(String... strings)

Specified by:

isIn in interface StringFilters

Specified by:

isIn in interface StringFilterSpec<Selection>

isIn

public Selection isIn(Collection<String> strings)

Specified by:

isIn in interface StringFilters

Specified by:

isIn in interface StringFilterSpec<Selection>

isNotIn

public Selection isNotIn(String... strings)

Specified by:

isNotIn in interface StringFilters

Specified by:

isNotIn in interface StringFilterSpec<Selection>

isNotIn

public Selection isNotIn(Collection<String> strings)

Specified by:

isNotIn in interface StringFilters

Specified by:

isNotIn in interface StringFilterSpec<Selection>

firstIndexOf

public int firstIndexOf(String value)

Specified by:

firstIndexOf in interface StringData

asObjectArray

public String[] asObjectArray()

Specified by:

asObjectArray in interface StringData

getDouble

public double getDouble(int i)

Returns a double that can stand in for the string at index i in some ML applications

TODO: Evaluate use of hashCode() here for uniqueness

Specified by:

getDouble in interface StringData

Parameters:

i - The index in this column

asDoubleArray

public double[] asDoubleArray()

Specified by:

asDoubleArray in interface StringData

countOccurrences

public int countOccurrences(String value)

Specified by:

countOccurrences in interface StringData

getDummies

public List<BooleanColumn> getDummies()

Unsupported Operation This can't be used on a text column as the number of BooleanColumns would likely be excessive

Specified by:

getDummies in interface StringData

getDictionary

@Nullable
public DictionaryMap getDictionary()

Returns null, as this Column is not backed by a dictionaryMap

Specified by:

getDictionary in interface StringData