ColumnList

Defined in: js-api/src/dataframe/column-list.ts:82

Columns in a [DataFrame].

Constructors

Constructor

new ColumnList(dart): ColumnList

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

Parameters

Parameter	Type
dart	any

Returns

ColumnList

Accessors

all

Get Signature

get all(): Iterable<Column<any, any>>

Defined in: js-api/src/dataframe/column-list.ts:143

Returns all columns.

Returns

Iterable<Column<any, any>>

---

boolean

Get Signature

get boolean(): Iterable<Column<any, any>>

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

Boolean columns.

Returns

Iterable<Column<any, any>>

---

categorical

Get Signature

get categorical(): Iterable<Column<any, any>>

Defined in: js-api/src/dataframe/column-list.ts:149

Finds categorical columns. Sample: https://public.datagrok.ai/js/samples/data-frame/find-columns

Returns

Iterable<Column<any, any>>

---

dataFrame

Get Signature

get dataFrame(): DataFrame

Defined in: js-api/src/dataframe/column-list.ts:90

The table these columns belong to.

Returns

DataFrame

---

dateTime

Get Signature

get dateTime(): Iterable<Column<any, any>>

Defined in: js-api/src/dataframe/column-list.ts:160

Datetime columns.

Returns

Iterable<Column<any, any>>

---

length

Get Signature

get length(): number

Defined in: js-api/src/dataframe/column-list.ts:93

Number of columns.

Returns

number

---

numerical

Get Signature

get numerical(): Iterable<Column<any, any>>

Defined in: js-api/src/dataframe/column-list.ts:155

Finds numerical columns. Sample: https://public.datagrok.ai/js/samples/data-frame/find-columns

Returns

Iterable<Column<any, any>>

---

numericalNoDateTime

Get Signature

get numericalNoDateTime(): Iterable<Column<any, any>>

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

Numerical columns excluding datetime.

Returns

Iterable<Column<any, any>>

---

selected

Get Signature

get selected(): Iterable<Column<any, any>>

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

Selected columns.

Returns

Iterable<Column<any, any>>

Methods

_getNewCalculated()

_getNewCalculated(name, expression, type?, treatAsString?): Promise<Column<any, any>>

Defined in: js-api/src/dataframe/column-list.ts:253

Parameters

Parameter	Type	Default value
name	string	undefined
expression	string	undefined
type	"string" | "bigint" | "object" | "bool" | "int" | "double" | "byte_array" | "datetime" | "qnum" | "dataframe" | "auto"	'auto'
treatAsString	boolean	false

Returns

Promise<Column<any, any>>

---

[iterator]()

[iterator](): IterableIterator<Column<any, any>>

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

Iterates over all columns.

Returns

IterableIterator<Column<any, any>>

---

add()

add(column, notify?): Column

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

Adds a column, and optionally notifies the parent dataframe.

Parameters

Parameter	Type	Default value	Description
column	Column	undefined	-
notify	boolean	true	whether DataFrame's changed event should be fired

Returns

Column

---

addNew()

addNew(name, type): Column

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

Adds an empty column of the specified type.

Parameters

Parameter	Type
name	string
type	"string" | "bigint" | "object" | "bool" | "int" | "double" | "byte_array" | "datetime" | "qnum" | "dataframe"

Returns

Column

---

addNewBool()

addNewBool(name): Column<boolean>

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

Creates and adds a boolean column https://public.datagrok.ai/js/samples/data-frame/modification/add-columns

Parameters

Parameter	Type
name	string

Returns

Column<boolean>

---

addNewBytes()

addNewBytes(name): Column<Uint8Array<ArrayBufferLike>>

Defined in: js-api/src/dataframe/column-list.ts:295

Creates and adds a byte array column https://public.datagrok.ai/js/samples/data-frame/modification/add-columns

Parameters

Parameter	Type
name	string

Returns

Column<Uint8Array<ArrayBufferLike>>

---

addNewCalculated()

Call Signature

addNewCalculated<T>(name, expression, options?): Promise<Column<any, any>>

Defined in: js-api/src/dataframe/column-list.ts:240

Adds a column calculated by the formula expression, and resolves with it. Rows the formula fails on stay empty unless options.onError says otherwise; {mode: 'stop'} rejects instead. The error behavior (other than stop) is kept with the column, so layouts and recalculations reuse it.

Type Parameters

Type Parameter	Default type
T extends "string" | "bigint" | "object" | "bool" | "int" | "double" | "byte_array" | "datetime" | "qnum" | "dataframe" | "auto"	"auto"

Parameters

Parameter	Type	Description
name	string	Name of the new column; a unique one is derived from it if the table already has it.
expression	string	Formula, such as ${AGE} * 2 or InDays(DateDiff(${END}, ${START})).
options?	IAddNewCalculatedOptions<T>	-

Returns

Promise<Column<any, any>>

Example

const days = await df.columns.addNewCalculated('Days', 'InDays(DateDiff(${END}, ${START}))',
  {type: 'int', onError: {mode: 'value', value: -1, errorColumn: true}});

See

https://public.datagrok.ai/js/samples/data-frame/modification/calculated-columns/error-handling

Call Signature

addNewCalculated(name, expression, type?, treatAsString?, subscribeOnChanges?): Promise<Column<any, any>>

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

Adds a column calculated by the formula expression, and resolves with it.

Parameters

Parameter	Type	Description
name	string	-
expression	string	-
type?	"string" | "bigint" | "object" | "bool" | "int" | "double" | "byte_array" | "datetime" | "qnum" | "dataframe" | "auto"	-
treatAsString?	boolean	if true, [expression] is not evaluated as formula and is treated as a regular string value instead
subscribeOnChanges?	boolean	if true, the column will be recalculated when the source columns change

Returns

Promise<Column<any, any>>

---

addNewDateTime()

addNewDateTime(name): DateTimeColumn

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

Creates and adds a datetime column https://public.datagrok.ai/js/samples/data-frame/modification/add-columns

Parameters

Parameter	Type
name	string

Returns

DateTimeColumn

---

addNewFloat()

addNewFloat(name): Column<number>

Defined in: js-api/src/dataframe/column-list.ts:265

Creates and adds a float column

Parameters

Parameter	Type
name	string

Returns

Column<number>

---

addNewInt()

addNewInt(name): Column<number>

Defined in: js-api/src/dataframe/column-list.ts:262

Creates and adds an integer column https://public.datagrok.ai/js/samples/data-frame/modification/add-columns

Parameters

Parameter	Type
name	string

Returns

Column<number>

---

addNewQnum()

addNewQnum(name, options?): Column<number>

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

Creates and adds a qualified number column. If [options] is provided, populates the column by combining a qualifier column (string values: '<', '>', '', '=') with a numeric value column at each row. https://public.datagrok.ai/js/samples/data-frame/modification/add-columns

Parameters

Parameter	Type
name	string
options?	QnumColumnCreationOptions

Returns

Column<number>

---

addNewString()

addNewString(name): Column<string>

Defined in: js-api/src/dataframe/column-list.ts:258

Creates and adds a string column.

Parameters

Parameter	Type
name	string

Returns

Column<string>

---

addNewVirtual()

addNewVirtual(name, getValue, type?, setValue?): Column

Defined in: js-api/src/dataframe/column-list.ts:305

Creates and adds a virtual column.

Parameters

Parameter	Type	Default value	Description
name	string	undefined	column name
getValue	(ind) => any	undefined	value constructor function that accepts int index and returns value
type	TYPE	TYPE.OBJECT	column type https://public.datagrok.ai/js/samples/data-frame/advanced/virtual-int-column https://public.datagrok.ai/js/samples/data-frame/advanced/virtual-columns
setValue	IndexSetter | null	null	function that gets invoked when a column cell value is set

Returns

Column

---

byIndex()

byIndex(index): Column

Defined in: js-api/src/dataframe/column-list.ts:103

Column by index

Parameters

Parameter	Type
index	number

Returns

Column

---

byName()

byName(name): Column

Defined in: js-api/src/dataframe/column-list.ts:97

Column with the corresponding name (case-insensitive), or null if there is no such column. See also DataFrame.getCol, which throws instead.

Parameters

Parameter	Type
name	string

Returns

Column

---

byNames()

byNames(names): Column<any, any>[]

Defined in: js-api/src/dataframe/column-list.ts:100

Maps names to columns.

Parameters

Parameter	Type
names	string[]

Returns

Column<any, any>[]

---

bySemType()

bySemType(semType): Column<any, any> | null

Defined in: js-api/src/dataframe/column-list.ts:106

First column of [semType], or null.

Parameters

Parameter	Type
semType	string

Returns

Column<any, any> | null

---

bySemTypeAll()

bySemTypeAll(semType): Column<any, any>[]

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

All columns of [semType], or empty list.

Parameters

Parameter	Type
semType	string

Returns

Column<any, any>[]

---

bySemTypesExact()

bySemTypesExact(semTypes): Column<any, any>[] | null

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

Finds columns by the corresponding semTypes, or null, if any of the sem types could not be found.

Parameters

Parameter	Type
semTypes	string[]

Returns

Column<any, any>[] | null

---

byTags()

byTags(tags): Iterable<Column<any, any>>

Defined in: js-api/src/dataframe/column-list.ts:131

Finds columns by specified tags and values: {'tag': 'value'}. Pass null or undefined to match any value of a tag. Sample: https://public.datagrok.ai/js/samples/data-frame/find-columns

Parameters

Parameter	Type
tags	object

Returns

Iterable<Column<any, any>>

---

contains()

contains(columnName): boolean

Defined in: js-api/src/dataframe/column-list.ts:324

Checks whether this list contains a column with the specified name. The check is case-insensitive.

Parameters

Parameter	Type
columnName	string

Returns

boolean

---

firstWhere()

firstWhere(predicate): Column<any, any> | undefined

Defined in: js-api/src/dataframe/column-list.ts:136

Returns the first column that satisfies the specified criteria.

Parameters

Parameter	Type
predicate	(col) => boolean

Returns

Column<any, any> | undefined

---

getOrCreate()

getOrCreate(name, type): Column

Defined in: js-api/src/dataframe/column-list.ts:212

Returns a column with the specified name and type, or creates a new column if it does not exist.

Parameters

Parameter	Type	Description
name	string	column name
type	"string" | "bigint" | "object" | "bool" | "int" | "double" | "byte_array" | "datetime" | "qnum" | "dataframe"	-

Returns

Column

See

COLUMN_TYPE

---

getUnusedName()

getUnusedName(name, choices?): string

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

Returns a name that does not exist in column list. If column list does not contain column with [name], returns [name]. Otherwise, tries [choices], and if the names are taken already, returns a string in a form of 'name (i)'.

Parameters

Parameter	Type
name	string
choices?	string[]

Returns

string

---

insert()

insert(column, index?, notify?): Column

Defined in: js-api/src/dataframe/column-list.ts:221

Inserts a column, and optionally notifies the parent dataframe.

Parameters

Parameter	Type	Default value	Description
column	Column	undefined	column to insert
index	number | null	null	-
notify	boolean	true	whether DataFrame's changed event should be fired

Returns

Column

---

names()

names(): string[]

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

Array containing column names.

Returns

string[]

---

remove()

remove(column, notify?): ColumnList

Defined in: js-api/src/dataframe/column-list.ts:313

Removes column by name (case-insensitive).

Parameters

Parameter	Type	Default value
column	string | number | Column<any, any>	undefined
notify	boolean	true

Returns

ColumnList

---

replace()

replace(columnToReplace, newColumn, notify?): Column

Defined in: js-api/src/dataframe/column-list.ts:329

Replaces the column with the new column.

Parameters

Parameter	Type	Default value
columnToReplace	string | Column<any, any>	undefined
newColumn	Column	undefined
notify	boolean	true

Returns

Column

---

setOrder()

setOrder(columnNames): void

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

Sets column order. Sample: https://public.datagrok.ai/js/samples/data-frame/columns-ordering

Parameters

Parameter	Type	Description
columnNames	string[]	Order of columns.

Returns

void

---

toList()

toList(): Column<any, any>[]

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

Creates an array of columns.

Returns

Column<any, any>[]

---

toMap()

toMap(): Map<string, Column<any, any>>

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

Returns a name->column map. Use it when you need to access columns frequently.

Returns

Map<string, Column<any, any>>

---

toString()

toString(): string

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

Returns

string