DataFrameColumn
Strongly-typed column. Use get and set to access elements by index.
Extends
Constructors
new DataFrameColumn()
new DataFrameColumn(
dart
):DataFrameColumn
Parameters
Parameter | Type |
---|---|
dart | any |
Returns
Inherited from
Source
Properties
Property | Modifier | Type | Inherited from |
---|---|---|---|
dart | public | any | Column .dart |
tags | public | any | Column .tags |
temp | public | any | Column .temp |
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
Inherited from
Source
applyFormula()
applyFormula(
formula
,type
,treatAsString
):Promise
<null
|Column
<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
>>
Inherited from
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.
Inherited from
Source
clone()
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
Inherited from
Source
compact()
compact():
any
Compacts the internal column representation. Currently, it only affects string columns where values were modified.
Returns
any
Inherited from
Source
convertTo()
convertTo(
newType
,format
):Column
<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
>
Inherited from
Source
get()
get(
row
):null
|DataFrame
Gets [i]-th value.
Parameters
Parameter | Type |
---|---|
row | number |
Returns
null
| DataFrame
Overrides
Source
getCategory()
getCategory(
categoryIndex
):string
Returns i-th category. Applicable to string column only.
Parameters
Parameter | Type |
---|---|
categoryIndex | number |
Returns
string
Inherited from
Source
getCategoryOrder()
getCategoryOrder():
string
[]
Gets order of categories
Returns
string
[]
Inherited from
Source
getNumber()
getNumber(
i
):number
Returns i-th value as number
Parameters
Parameter | Type | Description |
---|---|---|
i | number |
Returns
number
Inherited from
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
Inherited from
Source
getSortedOrder()
getSortedOrder():
Int32Array
Returns an array of indexes sorted using [valueComparer].
Returns
Int32Array
Inherited from
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
Inherited from
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
Inherited from
Source
init()
init(
valueInitializer
):Column
<any
>
Initializes all values in the column to [columnInitializer].
Parameters
Parameter | Type | Description |
---|---|---|
valueInitializer | string | number | boolean | (ind ) => any | value, or a function that returns value by index |
Returns
Column
<any
>
Inherited from
Source
isNone()
isNone(
i
):boolean
Returns whether i-th value is missing.
Parameters
Parameter | Type | Description |
---|---|---|
i | number | Row index. |
Returns
boolean
Inherited from
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
Inherited from
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
Inherited from
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 | DataFrame | undefined | |
notify | boolean | true | whether DataFrame's changed event should be fired |
Returns
void
Inherited from
Source
setCategoryOrder()
setCategoryOrder(
order
):void
Sets order of categories
Parameters
Parameter | Type |
---|---|
order | string [] |
Returns
void
Inherited from
Source
setRawData()
setRawData(
rawData
,notify
):void
Parameters
Parameter | Type | Default value |
---|---|---|
rawData | Int32Array | Uint32Array | Float32Array | Float64Array | undefined |
notify | boolean | true |
Returns
void
Inherited from
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
Inherited from
Source
setTag()
setTag(
tag
,value
):Column
<any
>
Sets a tag to the specified value.
Parameters
Parameter | Type | Description |
---|---|---|
tag | string | Key. |
value | string | Value. |
Returns
Column
<any
>
. *
Inherited from
Source
toList()
toList():
DataFrame
[]
Copies column values to an array. Avoid using this method for performance-critical routines; consider using getRawData
Returns
Overrides
Source
toString()
toString():
string
Returns
string
- string representation of this column
Inherited from
Source
values()
values():
Generator
<null
|DataFrame
,void
,unknown
>
An iterator over all values in this column.
Returns
Generator
<null
| DataFrame
, void
, unknown
>
Inherited from
Source
bool()
static
bool(name
,length
):Column
<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
>
Inherited from
Source
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
Inherited from
Source
dateTime()
static
dateTime(name
,length
):Column
<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
>
Inherited from
Source
float()
static
float(name
,length
):Column
<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
>
Inherited from
Source
fromBigInt64Array()
static
fromBigInt64Array(name
,array
):Column
<any
>
Creates BigIntColumn from BigInt64Array / BigUint64Array
Parameters
Parameter | Type |
---|---|
name | string |
array | BigInt64Array | BigUint64Array |
Returns
Column
<any
>
Inherited from
Source
fromBitSet()
static
fromBitSet(name
,bitset
):Column
<boolean
>
Creates a Column from the bitset.
Parameters
Parameter | Type | Description |
---|---|---|
name | string | |
bitset | BitSet |
Returns
Column
<boolean
>
Inherited from
Source
fromFloat32Array()
static
fromFloat32Array(name
,array
,length
):Column
<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
>
Inherited from
Source
fromFloat64Array()
static
fromFloat64Array(name
,array
,length
):Column
<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
>
Inherited from
Source
fromIndexes()
static
fromIndexes(name
,categories
,indexes
):Column
<any
>
Crates a Column of string type from categories and indexes
Parameters
Parameter | Type | Description |
---|---|---|
name | string | |
categories | string [] | |
indexes | Int32Array |
Returns
Column
<any
>
Inherited from
Source
fromInt32Array()
static
fromInt32Array(name
,array
,length
):Column
<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
>
Inherited from
Source
fromList()
static
fromList(type
,name
,list
):Column
<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
>
Inherited from
Source
fromStrings()
static
fromStrings(name
,list
):Column
<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
>
Inherited from
Source
fromType()
static
fromType(type
,name
?,length
?):Column
<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
>
Inherited from
See
COLUMN_TYPE
Source
int()
static
int(name
,length
):Column
<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
>
Inherited from
Source
qnum()
static
qnum(name
,length
,values
,exact
):Column
<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
>
Inherited from
Source
string()
static
string(name
,length
):Column
<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
>