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ParallelEnumerable.Average<TSource> Method (ParallelQuery<TSource>, Func<TSource, Int32>)

.NET Framework (current version)

Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence.

Namespace:   System.Linq
Assembly:  System.Core (in System.Core.dll)

public static double Average<TSource>(
	this ParallelQuery<TSource> source,
	Func<TSource, int> selector


Type: System.Linq.ParallelQuery<TSource>

A sequence of values that are used to calculate an average.

Type: System.Func<TSource, Int32>

A transform function to apply to each element.

Return Value

Type: System.Double

The average of the sequence of values.

Type Parameters


The type of elements of source.

Exception Condition

The query was canceled with the token passed in through WithCancellation.


source or selector is a null reference (Nothing in Visual Basic).


The sum or count of the elements in the sequence is larger than MaxValue. -or- One or more exceptions occurred during the evaluation of the query.


source contains no elements.


(Thrown as inner exception in an AggregateException). The selector function returns a value greater than MaxValue for the element type.

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone
Available since 8.1
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