Column (tablesaw-core 0.25.0 API)

All Superinterfaces:

Comparator<T>, Iterable<T>

All Known Subinterfaces:

BooleanMapUtils, CategoricalColumn<T>, DateFilters, DateMapFunctions, DateTimeFilters, DateTimeMapFunctions, NumberColumn, NumberPredicates, StringFilters, StringMapFunctions, StringReduceUtils, TimeFilters, TimeMapFunctions

All Known Implementing Classes:

AbstractColumn, BooleanColumn, DateColumn, DateTimeColumn, DoubleColumn, StringColumn, TimeColumn
```
public interface Column<T>
extends Iterable<T>, Comparator<T>
```
The general interface for columns.
Columns can either exist on their own or be a part of a table. All the data in a single column is of a particular type.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`Column<T>`	`append(T value)`
`Column<T>`	`append(Column<T> column)`
`Column<T>`	`appendCell(String stringValue)`
`Column<T>`	`appendCell(String stringValue, StringParser parser)`
`Column<T>`	`appendMissing()`	Appends a missing value appropriate to the column
`byte[]`	`asBytes(int rowNumber)`	Returns the contents of the cell at rowNumber as a byte[].
`double[]`	`asDoubleArray()`
`Object[]`	`asObjectArray()`
`int`	`byteSize()`	Returns the width of a cell in this column, in bytes.
`void`	`clear()`
`default int`	`columnWidth()`	Returns the width of the column in characters, for printing
`Column<T>`	`copy()`	Returns a deep copy of the receiver
`int`	`countMissing()`	Returns the count of missing values in this column.
`default int`	`countUnique()`	Returns the count of unique values in this column.
`static <T> Column<T>`	`create(String columnName, ColumnType<T> type)`
`default void`	`doWithEach(Consumer<T> consumer)`	Applies the given consumer to each element in this column
`Column<T>`	`emptyCopy()`	Returns a copy of the receiver with no data.
`Column<T>`	`emptyCopy(int rowSize)`	Returns an empty copy of the receiver, with its internal storage initialized to the given row size.
`default Column<T>`	`fillMissing(T defaultVal)`	Create a copy of this column where missing values are replaced with the given default value
`default Column<T>`	`fillMissing(Column<T> other)`	Create a copy of this column where missing values are replaced with the corresponding value in the given column
`default Column<T>`	`first(int numRows)`
`T`	`get(int row)`
`double`	`getDouble(int row)`	Returns a double representation of the value at the given row.
`String`	`getString(int row)`	Returns a string representation of the value at the given row.
`String`	`getUnformattedString(int r)`
`default Column<T>`	`inRange(int start, int end)`	Returns a column containing the rows in this column beginning with start inclusive, and ending with end exclusive
`boolean`	`isEmpty()`	Returns true if the column has no data
`Selection`	`isMissing()`
`boolean`	`isMissing(int rowNumber)`
`Selection`	`isNotMissing()`
`Column<T>`	`lag(int n)`	Returns a column of the same type and size as the receiver, containing the receivers values offset by n.
`default Column<T>`	`last(int numRows)`
`default Column<T>`	`lead(int n)`	Returns a column of the same type as the receiver, containing the receivers values offset -n For example if you lead a column containing 2, 3, 4 by 1, you get a column containing 3, 4, NA.
`String`	`name()`	Returns the column's name.
`default String`	`print()`	TODO(lwhite): Print n from the top and bottom, like a table;
`Column<T>`	`removeMissing()`
`default RollingColumn`	`rolling(int windowSize)`
`it.unimi.dsi.fastutil.ints.IntComparator`	`rowComparator()`
`default Column<T>`	`rows(int... indices)`	Returns a column containing the values in this column with the given indices
`default Column<T>`	`sampleN(int n)`	Returns a column containing a random sample of the values in this column
`default Column<T>`	`sampleX(double proportion)`	Returns a table consisting of randomly selected values from this column.
`Column<T>`	`set(int row, T value)`
`Column<T>`	`setName(String name)`	Sets the columns name to the given string
`int`	`size()`
`void`	`sortAscending()`
`void`	`sortDescending()`
`default Column<T>`	`subset(Selection rows)`
`Table`	`summary()`
`default String`	`title()`
`ColumnType`	`type()`	Returns this column's ColumnType
`Column<T>`	`unique()`	Returns a column of the same type as the receiver, containing only the unique values of the receiver.
`Column<T>`	`where(Selection selection)`

Methods inherited from interface java.util.Comparator
compare, comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

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

- Method Detail
  - create
```
static <T> Column<T> create(String columnName,
                            ColumnType<T> type)
```
  - size
```
int size()
```
  - summary
```
Table summary()
```
  - asObjectArray
```
Object[] asObjectArray()
```
  - subset
```
default Column<T> subset(Selection rows)
```
  - countMissing
```
int countMissing()
```
    Returns the count of missing values in this column.
    
    Returns:
    
    missing values as int
  - countUnique
```
default int countUnique()
```
    Returns the count of unique values in this column.
    
    Returns:
    
    unique values as int
  - unique
```
Column<T> unique()
```
    Returns a column of the same type as the receiver, containing only the unique values of the receiver.
    
    Returns:
    
    a Column
  - lead
```
default Column<T> lead(int n)
```
    Returns a column of the same type as the receiver, containing the receivers values offset -n For example if you lead a column containing 2, 3, 4 by 1, you get a column containing 3, 4, NA.
  - lag
```
Column<T> lag(int n)
```
    Returns a column of the same type and size as the receiver, containing the receivers values offset by n.
    For example if you lag a column containing 2, 3, 4 by 1, you get a column containing NA, 2, 3
  - name
```
String name()
```
    Returns the column's name.
    
    Returns:
    
    name as String
  - setName
```
Column<T> setName(String name)
```
    Sets the columns name to the given string
    
    Parameters:
    
    name - The new name MUST be unique for any table containing this column
    
    Returns:
    
    this Column to allow method chaining
  - type
```
ColumnType type()
```
    Returns this column's ColumnType
    
    Returns:
    
    ColumnType
  - getString
```
String getString(int row)
```
    Returns a string representation of the value at the given row.
    
    Parameters:
    
    row - The index of the row.
    
    Returns:
    
    value as String
  - get
```
T get(int row)
```
  - getDouble
```
double getDouble(int row)
```
    Returns a double representation of the value at the given row. The nature of the returned value is column-specific. The double returned MAY be the actual value (for Number columns) but is more likely a number that maps to the column value in some way.
    
    Parameters:
    
    row - The index of the row.
    
    Returns:
    
    value as String
  - emptyCopy
```
Column<T> emptyCopy()
```
    Returns a copy of the receiver with no data. The column name and type are the same.
    
    Returns:
    
    a empty copy of Column
  - copy
```
Column<T> copy()
```
    Returns a deep copy of the receiver
    
    Returns:
    
    a Column
  - emptyCopy
```
Column<T> emptyCopy(int rowSize)
```
    Returns an empty copy of the receiver, with its internal storage initialized to the given row size.
    
    Parameters:
    
    rowSize - the initial row size
    
    Returns:
    
    a Column
  - clear
```
void clear()
```
  - sortAscending
```
void sortAscending()
```
  - sortDescending
```
void sortDescending()
```
  - isEmpty
```
boolean isEmpty()
```
    Returns true if the column has no data
    
    Returns:
    
    true if empty, false if not
  - appendCell
```
Column<T> appendCell(String stringValue)
```
  - appendCell
```
Column<T> appendCell(String stringValue,
                     StringParser parser)
```
  - rowComparator
```
it.unimi.dsi.fastutil.ints.IntComparator rowComparator()
```
  - set
```
Column<T> set(int row,
              T value)
```
  - append
```
Column<T> append(T value)
```
  - append
```
Column<T> append(Column<T> column)
```
  - first
```
default Column<T> first(int numRows)
```
  - last
```
default Column<T> last(int numRows)
```
  - title
```
default String title()
```
  - asDoubleArray
```
double[] asDoubleArray()
```
  - inRange
```
default Column<T> inRange(int start,
                          int end)
```
    Returns a column containing the rows in this column beginning with start inclusive, and ending with end exclusive
  - rows
```
default Column<T> rows(int... indices)
```
    Returns a column containing the values in this column with the given indices
  - sampleN
```
default Column<T> sampleN(int n)
```
    Returns a column containing a random sample of the values in this column
    
    Parameters:
    
    n - the number of values to select
    
    Returns:
    
    A column of the same type as the receiver
  - sampleX
```
default Column<T> sampleX(double proportion)
```
    Returns a table consisting of randomly selected values from this column. The sample size is based on the given proportion of the total number of cells in this column
    
    Parameters:
    
    proportion - The proportion to go in the sample
  - isMissing
```
Selection isMissing()
```
  - isNotMissing
```
Selection isNotMissing()
```
  - byteSize
```
int byteSize()
```
    Returns the width of a cell in this column, in bytes.
    
    Returns:
    
    width in bytes
  - asBytes
```
byte[] asBytes(int rowNumber)
```
    Returns the contents of the cell at rowNumber as a byte[].
    
    Parameters:
    
    rowNumber - index of the row
    
    Returns:
    
    content as byte[]
  - rolling
```
default RollingColumn rolling(int windowSize)
```
  - getUnformattedString
```
String getUnformattedString(int r)
```
  - isMissing
```
boolean isMissing(int rowNumber)
```
  - appendMissing
```
Column<T> appendMissing()
```
    Appends a missing value appropriate to the column
  - where
```
Column<T> where(Selection selection)
```
  - removeMissing
```
Column<T> removeMissing()
```
  - doWithEach
```
default void doWithEach(Consumer<T> consumer)
```
    Applies the given consumer to each element in this column
  - print
```
default String print()
```
    TODO(lwhite): Print n from the top and bottom, like a table;
  - fillMissing
```
default Column<T> fillMissing(Column<T> other)
```
    Create a copy of this column where missing values are replaced with the corresponding value in the given column
  - fillMissing
```
default Column<T> fillMissing(T defaultVal)
```
    Create a copy of this column where missing values are replaced with the given default value
  - columnWidth
```
default int columnWidth()
```
    Returns the width of the column in characters, for printing

Interface Column<T>

Method Summary

Methods inherited from interface java.util.Comparator

Methods inherited from interface java.lang.Iterable

Method Detail

create

size

summary

asObjectArray

subset

countMissing

countUnique

unique

lead

lag

name

setName

type

getString

get

getDouble

emptyCopy

copy

emptyCopy

clear

sortAscending

sortDescending

isEmpty

appendCell

appendCell

rowComparator

set

append

append

first

last

title

asDoubleArray

inRange

rows

sampleN

sampleX

isMissing

isNotMissing

byteSize

asBytes

rolling

getUnformattedString

isMissing

appendMissing

where

removeMissing

doWithEach

print

fillMissing

fillMissing

columnWidth