Column<T, TInit>
Strongly-typed column. Use get and set to access elements by index.
Extended by
Type parameters
Type parameter | Value |
---|---|
T | any |
TInit | T |
Constructors
new Column()
new Column<
T
,TInit
>(dart
):Column
<T
,TInit
>
Parameters
Parameter | Type |
---|---|
dart | any |
Returns
Column
<T
, TInit
>
Source
Properties
Property | Modifier | Type |
---|---|---|
_meta | private | undefined | ColumnMetaHelper |
dart | public | any |
tags | public | any |
temp | public | any |
Accessors
categories
get
categories():string
[]
Returns all unique strings in a sorted order. Applicable to string column only.
Returns
string
[]
Source
colors
get
colors():ColumnColorHelper
Returns
Source
dataFrame
get
dataFrame():DataFrame
Parent table
Returns
Source
dialogs
get
dialogs():ColumnDialogHelper
Returns
Source
isCategorical
get
isCategorical():boolean
Is the column categorical (string, boolean)
Returns
boolean
Source
isNumerical
get
isNumerical():boolean
Is the column numerical (float, int, bigint, qnum)
Returns
boolean
Source
isVirtual
get
isVirtual():boolean
Is this column virtual
Returns
boolean
Source
layoutColumnId
get
layoutColumnId():string
Layout column ID
set
layoutColumnId(s
):void
Parameters
Parameter | Type |
---|---|
s | string |
Returns
string
Source
length
get
length():number
Number of elements
Returns
number
Source
markers
get
markers():ColumnMarkerHelper
Returns
Source
max
get
max():number
Column's maximum value. The result is cached.
Returns
number
Source
meta
get
meta():ColumnMetaHelper
Returns
Source
min
get
min():number
Column's minimum value. The result is cached.
Returns
number
Source
name
get
name():string
set
name(s
):void
Parameters
Parameter | Type |
---|---|
s | string |
Returns
string
Source
semType
get
semType():string
Semantic type
set
semType(s
):void
Parameters
Parameter | Type |
---|---|
s | string |
Returns
string
Source
stats
get
stats():Stats
Basic descriptive statistics. The result is cached.
Returns
Source
type
get
type():"string"
|"bigint"
|"object"
|"int"
|"double"
|"bool"
|"byte_array"
|"datetime"
|"qnum"
|"dataframe"
Column data type.
Returns
"string"
| "bigint"
| "object"
| "int"
| "double"
| "bool"
| "byte_array"
| "datetime"
| "qnum"
| "dataframe"
Source
valueComparer
get
valueComparer():null
|Comparer
Value comparison function to be used for sorting. Null means default sorting. Sample: https://public.datagrok.ai/js/samples/data-frame/sorting/custom-comparer
set
valueComparer(cmp
):void
Parameters
Parameter | Type |
---|---|
cmp | null | Comparer |
Returns
null
| Comparer
Source
version
get
version():number
Version of the column. Increases each time the column was changed
Returns
number
Source
Methods
aggregate()
aggregate(
type
):any
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 | string |
Returns
any
Source
applyFormula()
applyFormula(
formula
,type
,treatAsString
):Promise
<null
|Column
<any
,any
>>
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 | null | "string" | "bigint" | "object" | "int" | "double" | "bool" | "byte_array" | "datetime" | "qnum" | "dataframe" | null |
treatAsString | boolean | false |
Returns
Promise
<null
| Column
<any
, any
>>
Source
asDoubleList()
asDoubleList():
Float32Array
Returns
Float32Array
- typed array of float values representing the column. Does not guarantee to perform a copy of the underlying data.
Source
clone()
clone(
mask
?):Column
<T
,T
>
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
, T
>
Source
compact()
compact():
any
Compacts the internal column representation. Currently, it only affects string columns where values were modified.
Returns
any
Source
convertTo()
convertTo(
newType
,format
):Column
<any
,any
>
Creates and returns a new column by converting [column] to the specified [newType].
Parameters
Parameter | Type | Default value |
---|---|---|
newType | string | undefined |
format | null | string | null |
Returns
Column
<any
, any
>
Source
fireValuesChanged()
fireValuesChanged():
void
Call this method after setting elements without notifications via set
Returns
void
Source
get()
get(
row
):null
|T
Gets i-th value
Parameters
Parameter | Type | Description |
---|---|---|
row | number | row index |
Returns
null
| T
- or null if isNone(i)
Source
getCategory()
getCategory(
categoryIndex
):string
Returns i-th category. Applicable to string column only.
Parameters
Parameter | Type |
---|---|
categoryIndex | number |
Returns
string
Source
getCategoryOrder()
getCategoryOrder():
string
[]
Gets order of categories
Returns
string
[]
Source
getNumber()
getNumber(
i
):number
Returns i-th value as number
Parameters
Parameter | Type | Description |
---|---|---|
i | number |
Returns
number
Source
getRawData()
getRawData():
Int32Array
|Uint32Array
|Float32Array
|Float64Array
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
| Uint32Array
| Float32Array
| Float64Array
Source
getSortedOrder()
getSortedOrder():
Int32Array
Returns an array of indexes sorted using [valueComparer].
Returns
Int32Array
Source
getString()
getString(
i
):string
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 | Description |
---|---|---|
i | number |
Returns
string
Source
getTag()
getTag(
tag
):string
Returns the value of the specified tag, or null if the tag is not present.
Parameters
Parameter | Type |
---|---|
tag | string |
Returns
string
Source
init()
init(
valueInitializer
):Column
<any
,any
>
Initializes all values in the column to [columnInitializer].
Parameters
Parameter | Type | Description |
---|---|---|
valueInitializer | null | string | number | boolean | Date | Dayjs | (ind ) => any | value, or a function that returns value by index |
Returns
Column
<any
, any
>
Source
isNone()
isNone(
i
):boolean
Returns whether i-th value is missing.
Parameters
Parameter | Type | Description |
---|---|---|
i | number | Row index. |
Returns
boolean
Source
matches()
matches(
filter
):boolean
Checks whether the column passes the specified [filter]. [filter] can be either specific data [type] such as 'int' or 'string', more broadly - 'numerical', or 'categorical', or null for any columns.
Parameters
Parameter | Type |
---|---|
filter | null | "string" | "bigint" | "object" | "int" | "double" | "bool" | "byte_array" | "datetime" | "qnum" | "dataframe" | "categorical" | "numerical" |
Returns
boolean
Source
scale()
scale(
idx
):number
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
Source
set()
set(
i
,value
,notify
):void
Sets [i]-th value to [x], and optionally notifies the dataframe about this change.
Parameters
Parameter | Type | Default value | Description |
---|---|---|---|
i | number | undefined | |
value | null | TInit | undefined | |
notify | boolean | true | whether DataFrame's changed event should be fired. Call fireValuesChanged after you are done modifying the column. |
Returns
void
Source
setCategoryOrder()
setCategoryOrder(
order
):void
Sets order of categories
Parameters
Parameter | Type |
---|---|
order | string [] |
Returns
void
Source
setRawData()
setRawData(
rawData
,notify
):void
Parameters
Parameter | Type | Default value |
---|---|---|
rawData | Int32Array | Uint32Array | Float32Array | Float64Array | undefined |
notify | boolean | true |
Returns
void
Source
setString()
setString(
i
,str
,notify
):boolean
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
Source
setTag()
setTag(
tag
,value
):Column
<any
,any
>
Sets a tag to the specified value.
Parameters
Parameter | Type | Description |
---|---|---|
tag | string | Key. |
value | string | Value. |
Returns
Column
<any
, any
>
. *
Source
toList()
toList():
any
[]
Copies column values to an array. Avoid using this method for performance-critical routines; consider using getRawData
Returns
any
[]
Source
toString()
toString():
string
Returns
string
- string representation of this column
Source
values()
values():
Generator
<null
|T
,void
,unknown
>
An iterator over all values in this column.
Returns
Generator
<null
| T
, void
, unknown
>
Source
bool()
static
bool(name
,length
):Column
<boolean
,boolean
>
Creates a boolean column with the specified name and length.
Parameters
Parameter | Type | Default value | Description |
---|---|---|---|
name | string | undefined | |
length | number | 0 |
Returns
Column
<boolean
, boolean
>
Source
dataFrame()
static
dataFrame(name
,length
):Column
<DataFrame
,DataFrame
>
Creates a column containing dataframes with the specified name and length.
Parameters
Parameter | Type | Default value | Description |
---|---|---|---|
name | string | undefined | |
length | number | 0 |
Returns
Source
dateTime()
static
dateTime(name
,length
):Column
<any
,any
>
Creates a datetime column with the specified name and length.
Parameters
Parameter | Type | Default value | Description |
---|---|---|---|
name | string | undefined | |
length | number | 0 |
Returns
Column
<any
, any
>
Source
float()
static
float(name
,length
):Column
<number
,number
>
Creates a floating point column with the specified name and length.
Parameters
Parameter | Type | Default value | Description |
---|---|---|---|
name | string | undefined | |
length | number | 0 |
Returns
Column
<number
, number
>
Source
fromBigInt64Array()
static
fromBigInt64Array(name
,array
):Column
<any
,any
>
Creates BigIntColumn from BigInt64Array / BigUint64Array
Parameters
Parameter | Type |
---|---|
name | string |
array | BigInt64Array | BigUint64Array |
Returns
Column
<any
, any
>
Source
fromBitSet()
static
fromBitSet(name
,bitset
):Column
<boolean
,boolean
>
Creates a Column from the bitset.
Parameters
Parameter | Type | Description |
---|---|---|
name | string | |
bitset | BitSet |
Returns
Column
<boolean
, boolean
>
Source
fromFloat32Array()
static
fromFloat32Array(name
,array
,length
):Column
<number
,number
>
[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 | null | number | null |
Returns
Column
<number
, number
>
Source
fromFloat64Array()
static
fromFloat64Array(name
,array
,length
):Column
<number
,number
>
[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 | null | number | null |
Returns
Column
<number
, number
>
Source
fromIndexes()
static
fromIndexes(name
,categories
,indexes
):Column
<any
,any
>
Crates a Column of string type from categories and indexes
Parameters
Parameter | Type | Description |
---|---|---|
name | string | |
categories | string [] | |
indexes | Int32Array |
Returns
Column
<any
, any
>
Source
fromInt32Array()
static
fromInt32Array(name
,array
,length
):Column
<number
,number
>
[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 | null | number | null |
Returns
Column
<number
, number
>
Source
fromList()
static
fromList(type
,name
,list
):Column
<any
,any
>
Creates a Column from the list of values.
Parameters
Parameter | Type | Description |
---|---|---|
type | "string" | "bigint" | "object" | "int" | "double" | "bool" | "byte_array" | "datetime" | "qnum" | "dataframe" | |
name | string | |
list | any [] |
Returns
Column
<any
, any
>
Source
fromStrings()
static
fromStrings(name
,list
):Column
<any
,any
>
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://dev.datagrok.ai/script/samples/javascript/data-frame/construction/create-from-columns https://dev.datagrok.ai/script/samples/javascript/data-frame/construction/create-from-arrays |
Returns
Column
<any
, any
>
Source
fromType()
static
fromType(type
,name
?,length
?):Column
<any
,any
>
Creates a Column with explicitly specified type
Parameters
Parameter | Type | Default value | Description |
---|---|---|---|
type | "string" | "bigint" | "object" | "int" | "double" | "bool" | "byte_array" | "datetime" | "qnum" | "dataframe" | undefined | column type code COLUMN_TYPE |
name ? | null | string | undefined | Column name |
length ? | number | 0 | Column length (should match row count of the data frame ) |
Returns
Column
<any
, any
>
See
COLUMN_TYPE
Source
int()
static
int(name
,length
):Column
<number
,number
>
Creates an integer column with the specified name and length.
Parameters
Parameter | Type | Default value | Description |
---|---|---|---|
name | string | undefined | |
length | number | 0 |
Returns
Column
<number
, number
>
Source
qnum()
static
qnum(name
,length
,values
,exact
):Column
<number
,number
>
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
, number
>
Source
string()
static
string(name
,length
):Column
<string
,string
>
Creates a string column with the specified name and length.
Parameters
Parameter | Type | Default value | Description |
---|---|---|---|
name | string | undefined | |
length | number | 0 |
Returns
Column
<string
, string
>