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List.average<^T> Function (F#)

Den Delimarsky|Last Updated: 8/18/2017
1 Contributor

Returns the average of the elements in the list.

Namespace/Module Path: Microsoft.FSharp.Collections.List

Assembly: FSharp.Core (in FSharp.Core.dll)


// Signature:
List.average : ^T list -> ^T (requires ^T with static member (+) and ^T with static member DivideByInt and ^T with static member Zero)

// Usage:
List.average list


list Type: ^Tlist

The input list.


ArgumentExceptionThrown when the list is empty.

Return Value

The resulting average.


This function cannot be used directly on a list of integers since it requires that the type support an exact division operation, which is indicated by the constraint that the element type must support DivideByInt Floating point types support DivideByInt. To compute the average of a list of integers, see the example in List.averageBy.

This function is named Average in compiled assemblies. If you are accessing the function from a language other than F#, or through reflection, use this name.


The following code example illustrates the use of List.average.

// Compute the average of the elements of a list by using List.average.
let avg1 = List.average [0.0; 1.0; 1.0; 2.0]

printfn "%f" avg1




Windows 8, Windows 7, Windows Server 2012, Windows Server 2008 R2

Version Information

F# Core Library Versions

Supported in: 2.0, 4.0, Portable

See Also

Collections.List Module (F#)

Microsoft.FSharp.Collections Namespace (F#)

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