ColumnSelector.Where Method

public static ColumnSelector Where(
	Func<IColumnSchema, bool> predicate
)

Public Shared Function Where ( 
	predicate As Func(Of IColumnSchema, Boolean)
) As ColumnSelector

public:
static ColumnSelector^ Where(
	Func<IColumnSchema^, bool>^ predicate
)

static member Where : 
        predicate : Func<IColumnSchema, bool> -> ColumnSelector 

Parameters

predicate  Func<IColumnSchema, Boolean>

The predicate used to select columns.

Return Value

The predicate receives non-generic schema metadata and can resolve against schemas with any column-key type. It should not depend on vector values. A predicate that matches no columns resolves to an empty selection.

public static ColumnSelector Where<C>(
	Func<ColumnSchema<C>, bool> predicate
)

Public Shared Function Where(Of C) ( 
	predicate As Func(Of ColumnSchema(Of C), Boolean)
) As ColumnSelector

public:
generic<typename C>
static ColumnSelector^ Where(
	Func<ColumnSchema<C>^, bool>^ predicate
)

static member Where : 
        predicate : Func<ColumnSchema<'C>, bool> -> ColumnSelector 

Parameters

predicate  Func<ColumnSchema<C>, Boolean>

The predicate used to select columns.

Type Parameters

C

The element type of the data frame column index.

Return Value

The predicate receives typed column schemas, including typed column keys. Resolving this selector against a schema with a different column-key type throws InvalidCastException.

Reference