Column<T, TInit>

Defined in: js-api/src/dataframe/column.ts:24

Strongly-typed column. Use get and set to access elements by index.

Extended by

• FloatColumn
• BigIntColumn
• DateTimeColumn
• ObjectColumn
• DataFrameColumn

Type Parameters

Type Parameter	Default type
T	any
TInit	T

Constructors

Constructor

new Column<T, TInit>(dart): Column<T, TInit>

Defined in: js-api/src/dataframe/column.ts:32

Parameters

Parameter	Type
dart	any

Returns

Column<T, TInit>

Properties

Property	Modifier	Type	Description	Defined in
dart	public	any	-	js-api/src/dataframe/column.ts:25
tags	public	MapBag<string>	Metadata as string key-value pairs; persisted with the column.	js-api/src/dataframe/column.ts:29
temp	public	any	Auxiliary data that is not persisted (a MapBag: indexed access plus the map methods; typed any so it can be cast to a package's own shape).	js-api/src/dataframe/column.ts:27

Accessors

categories

Get Signature

get categories(): string[]

Defined in: js-api/src/dataframe/column.ts:373

Returns all unique strings in a sorted order. Applicable to string column only.

Returns

string[]

---

colors

Get Signature

get colors(): any

Defined in: js-api/src/dataframe/column.ts:232

Deprecated

Use meta.colors (ColumnMetaHelper.colors). Removed in 1.30.

Returns

any

---

dataFrame

Get Signature

get dataFrame(): DataFrame

Defined in: js-api/src/dataframe/column.ts:190

Parent table

Returns

DataFrame

---

dialogs

Get Signature

get dialogs(): any

Defined in: js-api/src/dataframe/column.ts:227

Deprecated

Use meta.dialogs (ColumnMetaHelper.dialogs). Removed in 1.30.

Returns

any

---

isCategorical

Get Signature

get isCategorical(): boolean

Defined in: js-api/src/dataframe/column.ts:170

Is the column categorical (string, boolean)

Returns

boolean

---

isEmpty

Get Signature

get isEmpty(): boolean

Defined in: js-api/src/dataframe/column.ts:337

Returns whether all values in the columns are empty.

Returns

boolean

---

isNumerical

Get Signature

get isNumerical(): boolean

Defined in: js-api/src/dataframe/column.ts:165

Is the column numerical (float, int, bigint, qnum)

Returns

boolean

---

isVirtual

Get Signature

get isVirtual(): boolean

Defined in: js-api/src/dataframe/column.ts:180

Is this column virtual

Returns

boolean

---

layoutColumnId

Get Signature

get layoutColumnId(): string

Defined in: js-api/src/dataframe/column.ts:204

Layout column ID

Returns

string

Set Signature

set layoutColumnId(s): void

Defined in: js-api/src/dataframe/column.ts:208

Parameters

Parameter	Type
s	string

Returns

void

---

length

Get Signature

get length(): number

Defined in: js-api/src/dataframe/column.ts:185

Number of elements

Returns

number

---

markers

Get Signature

get markers(): any

Defined in: js-api/src/dataframe/column.ts:237

Deprecated

Use meta.markers (ColumnMetaHelper.markers). Removed in 1.29.

Returns

any

---

max

Get Signature

get max(): number

Defined in: js-api/src/dataframe/column.ts:402

Column's maximum value. The result is cached.

Returns

number

---

meta

Get Signature

get meta(): ColumnMetaHelper

Defined in: js-api/src/dataframe/column.ts:38

Returns

ColumnMetaHelper

---

min

Get Signature

get min(): number

Defined in: js-api/src/dataframe/column.ts:399

Column's minimum value. The result is cached.

Returns

number

---

name

Get Signature

get name(): string

Defined in: js-api/src/dataframe/column.ts:213

Returns

string

Set Signature

set name(s): void

Defined in: js-api/src/dataframe/column.ts:217

Parameters

Parameter	Type
s	string

Returns

void

---

semType

Get Signature

get semType(): string

Defined in: js-api/src/dataframe/column.ts:195

Semantic type

Returns

string

Set Signature

set semType(s): void

Defined in: js-api/src/dataframe/column.ts:199

Parameters

Parameter	Type
s	string

Returns

void

---

stats

Get Signature

get stats(): Stats

Defined in: js-api/src/dataframe/column.ts:412

Basic descriptive statistics. The result is cached.

Returns

Stats

---

type

Get Signature

get type(): "string" | "bigint" | "object" | "bool" | "int" | "double" | "byte_array" | "datetime" | "qnum" | "dataframe"

Defined in: js-api/src/dataframe/column.ts:175

Column data type.

Returns

"string" | "bigint" | "object" | "bool" | "int" | "double" | "byte_array" | "datetime" | "qnum" | "dataframe"

---

valueComparer

Get Signature

get valueComparer(): Comparer | null

Defined in: js-api/src/dataframe/column.ts:395

Value comparison function to be used for sorting. Null means default sorting. Sample: https://public.datagrok.ai/js/samples/data-frame/sorting/custom-comparer

Returns

Comparer | null

Set Signature

set valueComparer(cmp): void

Defined in: js-api/src/dataframe/column.ts:396

Parameters

Parameter	Type
cmp	Comparer | null

Returns

void

---

version

Get Signature

get version(): number

Defined in: js-api/src/dataframe/column.ts:222

Version of the column. Increases each time the column was changed

Returns

number

Methods

aggregate()

aggregate(type): any

Defined in: js-api/src/dataframe/column.ts:450

Aggregates a column using the [type] function, which corresponds to

• [DG.AGG] for int, bigint, float, qnum columns,
• [DG.STR_AGG] and [DG.STAT_COUNTS] for string columns,
• [DG.STAT_COUNTS], [DG.AGG.MIN], [DG.AGG.MAX], [DG.AGG.AVG] for datetime columns,
• [DG.AGG.TOTAL_COUNT] and [DG.AGG.MISSING_VALUE_COUNT] for virtual columns.

Parameters

Parameter	Type
type	ColumnAggregationType

Returns

any

---

applyFormula()

applyFormula(formula, type?, treatAsString?): Promise<Column<any, any> | null>

Defined in: js-api/src/dataframe/column.ts:426

Applies the specified formula to a calculated column. Returns a new column object, if applied successfully, and null otherwise.

Parameters

Parameter	Type	Default value
formula	string	undefined
type	"string" | "bigint" | "object" | "bool" | "int" | "double" | "byte_array" | "datetime" | "qnum" | "dataframe" | null	null
treatAsString	boolean	false

Returns

Promise<Column<any, any> | null>

---

asDoubleList()

asDoubleList(): Float32Array

Defined in: js-api/src/dataframe/column.ts:456

Returns

Float32Array

typed array of float values representing the column. Does not guarantee to perform a copy of the underlying data.

---

clone()

clone(mask?): Column<T>

Defined in: js-api/src/dataframe/column.ts:260

Performs deep cloning, optionally taking mask of the rows to be included. Note that the cloned colum is not added to this column's dataframe.

Parameters

Parameter	Type
mask?	BitSet

Returns

Column<T>

---

compact()

compact(): any

Defined in: js-api/src/dataframe/column.ts:362

Compacts the internal column representation. Currently, it only affects string columns where values were modified.

Returns

any

---

convertTo()

convertTo(newType, format?): Column

Defined in: js-api/src/dataframe/column.ts:435

Creates and returns a new column by converting [column] to the specified [newType].

Parameters

Parameter	Type	Default value
newType	string	undefined
format	string | null	null

Returns

Column

---

fireValuesChanged()

fireValuesChanged(): void

Defined in: js-api/src/dataframe/column.ts:322

Call this method after setting elements without notifications via set

Returns

void

---

get()

get(row): T | null

Defined in: js-api/src/dataframe/column.ts:297

Gets i-th value

Parameters

Parameter	Type	Description
row	number	row index

Returns

T | null

or null if isNone(i)

---

getCategory()

getCategory(categoryIndex): string

Defined in: js-api/src/dataframe/column.ts:378

Returns i-th category. Applicable to string column only.

Parameters

Parameter	Type
categoryIndex	number

Returns

string

---

getCategoryOrder()

getCategoryOrder(): string[]

Defined in: js-api/src/dataframe/column.ts:388

Gets order of categories

Returns

string[]

---

getNumber()

getNumber(i): number

Defined in: js-api/src/dataframe/column.ts:308

Returns i-th value as number. None if isNone(i)

Parameters

Parameter	Type
i	number

Returns

number

---

getRawData()

getRawData(): Int32Array<ArrayBufferLike> | Uint32Array<ArrayBufferLike> | Float32Array<ArrayBufferLike> | Float64Array<ArrayBufferLike>

Defined in: js-api/src/dataframe/column.ts:272

FOR EXPERT USE ONLY! Returns the raw buffer containing data. Sample: https://public.datagrok.ai/js/samples/data-frame/performance/access Return type depends on the column type: {Int32Array} for ints, INT_NULL represents null. {Float32Array} or {Float64Array} for floats depending on doublePrecision parameter, FLOAT_NULL represents null. {Float64Array} for qnums, FLOAT_NULL represents null. {Float64Array} for datetime, in microseconds since epoch, FLOAT_NULL represents null. {Int32Array} for strings indexes of categories. {Uint32Array} bit array.

Returns

Int32Array<ArrayBufferLike> | Uint32Array<ArrayBufferLike> | Float32Array<ArrayBufferLike> | Float64Array<ArrayBufferLike>

---

getSortedOrder()

getSortedOrder(): Int32Array

Defined in: js-api/src/dataframe/column.ts:391

Returns an array of indexes sorted using [valueComparer].

Returns

Int32Array

---

getString()

getString(i): string

Defined in: js-api/src/dataframe/column.ts:303

Returns i-th value as string, taking into account value format defined for the column. An empty string is returned if there is no value.

Parameters

Parameter	Type
i	number

Returns

string

---

getTag()

getTag(tag): string

Defined in: js-api/src/dataframe/column.ts:347

Returns the value of the specified tag, or null if the tag is not present.

Parameters

Parameter	Type
tag	string

Returns

string

---

init()

init(valueInitializer): Column

Defined in: js-api/src/dataframe/column.ts:244

Initializes all values in the column to [columnInitializer].

Parameters

Parameter	Type	Description
valueInitializer	string | number | boolean | Dayjs | Date | ((ind) => any) | null	value, or a function that returns value by index

Returns

Column

---

isNone()

isNone(i): boolean

Defined in: js-api/src/dataframe/column.ts:342

Returns whether i-th value is missing.

Parameters

Parameter	Type
i	number

Returns

boolean

---

matches()

matches(filter): boolean

Defined in: js-api/src/dataframe/column.ts:407

Checks whether the column passes the specified [filter]. [filter] can be either specific data [type] such as 'int' or 'string', more broadly - 'numerical', 'numerical_no_datetime', or 'categorical', or null for any columns.

Parameters

Parameter	Type
filter	ColumnTypeFilter | null

Returns

boolean

---

scale()

scale(idx): number

Defined in: js-api/src/dataframe/column.ts:285

Linearly maps idx-th value to the [0,1] interval, where 0 represents column minimum, and 1 represents maximum.

Parameters

Parameter	Type
idx	number

Returns

number

---

set()

set(i, value, notify?): void

Defined in: js-api/src/dataframe/column.ts:332

Sets [i]-th value to [x], and optionally notifies the dataframe about this change.

Parameters

Parameter	Type	Default value	Description
i	number	undefined	Row index.
value	TInit | null	undefined	Value to set.
notify	boolean	true	whether DataFrame's changed event should be fired. Call fireValuesChanged after you are done modifying the column.

Returns

void

---

setCategoryOrder()

setCategoryOrder(order): void

Defined in: js-api/src/dataframe/column.ts:383

Sets order of categories

Parameters

Parameter	Type
order	string[]

Returns

void

---

setRawData()

setRawData(rawData, notify?): void

Defined in: js-api/src/dataframe/column.ts:290

Replaces the underlying buffer (see getRawData); [notify] fires the change event.

Parameters

Parameter	Type	Default value
rawData	Int32Array<ArrayBufferLike> | Uint32Array<ArrayBufferLike> | Float32Array<ArrayBufferLike> | Float64Array<ArrayBufferLike>	undefined
notify	boolean	true

Returns

void

---

setString()

setString(i, str, notify?): boolean

Defined in: js-api/src/dataframe/column.ts:317

Attempts to set i-th value by converting a provided string to the corresponding strongly-typed value. Returns true if text was successfully parsed and set, otherwise false. Examples: dateColumn.setString('April 1, 2020'); intColumn.setString('42');

Parameters

Parameter	Type	Default value	Description
i	number	undefined	-
str	string	undefined	-
notify	boolean	true	whether DataFrame's changed event should be fired

Returns

boolean

---

setTag()

setTag(tag, value): Column

Defined in: js-api/src/dataframe/column.ts:355

Sets a tag to the specified value.

Parameters

Parameter	Type	Description
tag	string	Key.
value	string	Value.

Returns

Column

---

toList()

toList(): any[]

Defined in: js-api/src/dataframe/column.ts:368

Copies column values to an array. Avoid using this method for performance-critical routines; consider using getRawData

Returns

any[]

---

toString()

toString(): string

Defined in: js-api/src/dataframe/column.ts:440

Returns

string

string representation of this column

---

values()

values(): Generator<T | null, void, unknown>

Defined in: js-api/src/dataframe/column.ts:418

An iterator over all values in this column.

Returns

Generator<T | null, void, unknown>

---

bool()

static bool(name, length?): Column<boolean>

Defined in: js-api/src/dataframe/column.ts:132

Creates a boolean column with the specified name and length.

Parameters

Parameter	Type	Default value
name	string	undefined
length	number	0

Returns

Column<boolean>

---

dataFrame()

static dataFrame(name, length?): Column<DataFrame>

Defined in: js-api/src/dataframe/column.ts:142

Creates a column containing dataframes with the specified name and length.

Parameters

Parameter	Type	Default value
name	string	undefined
length	number	0

Returns

Column<DataFrame>

---

dateTime()

static dateTime(name, length?): Column

Defined in: js-api/src/dataframe/column.ts:137

Creates a datetime column with the specified name and length.

Parameters

Parameter	Type	Default value
name	string	undefined
length	number	0

Returns

Column

---

float()

static float(name, length?): Column<number>

Defined in: js-api/src/dataframe/column.ts:122

Creates a floating point column with the specified name and length.

Parameters

Parameter	Type	Default value
name	string	undefined
length	number	0

Returns

Column<number>

---

fromBigInt64Array()

static fromBigInt64Array(name, array): Column<any, any>

Defined in: js-api/src/dataframe/column.ts:85

Creates BigIntColumn from BigInt64Array / BigUint64Array

Parameters

Parameter	Type
name	string
array	BigInt64Array<ArrayBufferLike> | BigUint64Array<ArrayBufferLike>

Returns

Column<any, any>

---

fromBitSet()

static fromBitSet(name, bitset): Column<boolean>

Defined in: js-api/src/dataframe/column.ts:112

Creates a Column from the bitset.

Parameters

Parameter	Type	Description
name	string	column name
bitset	BitSet	bitset. The resulting boolean column will be of length bitset.length

Returns

Column<boolean>

---

fromFloat32Array()

static fromFloat32Array(name, array, length?): Column<number>

Defined in: js-api/src/dataframe/column.ts:75

[array] will be not be copied and will be used as column's storage

Parameters

Parameter	Type	Default value
name	string	undefined
array	Float32Array	undefined
length	number | null	null

Returns

Column<number>

---

fromFloat64Array()

static fromFloat64Array(name, array, length?): Column<number>

Defined in: js-api/src/dataframe/column.ts:80

[array] will be not be copied and will be used as column's storage

Parameters

Parameter	Type	Default value
name	string	undefined
array	Float64Array	undefined
length	number | null	null

Returns

Column<number>

---

fromIndexes()

static fromIndexes(name, categories, indexes): Column

Defined in: js-api/src/dataframe/column.ts:105

Crates a Column of string type from categories and indexes

Parameters

Parameter	Type	Description
name	string	-
categories	string[]	-
indexes	Int32Array	-

Returns

Column

---

fromInt32Array()

static fromInt32Array(name, array, length?): Column<number>

Defined in: js-api/src/dataframe/column.ts:70

[array] will be not be copied and will be used as column's storage

Parameters

Parameter	Type	Default value
name	string	undefined
array	Int32Array	undefined
length	number | null	null

Returns

Column<number>

---

fromList()

static fromList(type, name, list): Column

Defined in: js-api/src/dataframe/column.ts:95

Creates a Column from the list of values.

Parameters

Parameter	Type	Description
type	"string" | "bigint" | "object" | "bool" | "int" | "double" | "byte_array" | "datetime" | "qnum" | "dataframe"	-
name	string	column name
list	any[]	list of values

Returns

Column

See

COLUMN_TYPE

---

fromStrings()

static fromStrings(name, list): Column

Defined in: js-api/src/dataframe/column.ts:54

Creates a Column from the list of string values Please note that method performs type promotion if all listed values are numeric

Parameters

Parameter	Type	Description
name	string	Column name
list	string[]	List of column values https://public.datagrok.ai/js/samples/data-frame/construction/create-from-columns https://public.datagrok.ai/js/samples/data-frame/construction/create-from-arrays

Returns

Column

---

fromType()

static fromType<T>(type, name?, length?): Column<T>

Defined in: js-api/src/dataframe/column.ts:65

Creates a Column with explicitly specified type

Type Parameters

Type Parameter	Default type
T	any

Parameters

Parameter	Type	Default value	Description
type	"string" | "bigint" | "object" | "bool" | "int" | "double" | "byte_array" | "datetime" | "qnum" | "dataframe"	undefined	column type code COLUMN_TYPE
name?	string | null	undefined	Column name
length?	number	0	Column length (should match row count of the data frame ) DataFrame.create

Returns

Column<T>

See

COLUMN_TYPE

---

int()

static int(name, length?): Column<number>

Defined in: js-api/src/dataframe/column.ts:117

Creates an integer column with the specified name and length.

Parameters

Parameter	Type	Default value
name	string	undefined
length	number	0

Returns

Column<number>

---

qnum()

static qnum(name, length?, values?, exact?): Column<number>

Defined in: js-api/src/dataframe/column.ts:151

Creates a qualified number column with the specified name and length. Initialized values with [values], if it is specified; strips out the qualifier part if [exact] is true.

Parameters

Parameter	Type	Default value	Description
name	string	undefined	-
length	number	0	-
values	number[]	[]	-
exact	boolean	true	if true, strips out qualifier from [values].

Returns

Column<number>

---

string()

static string(name, length?): Column<string>

Defined in: js-api/src/dataframe/column.ts:127

Creates a string column with the specified name and length.

Parameters

Parameter	Type	Default value
name	string	undefined
length	number	0

Returns

Column<string>