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  "documentType" : "symbol",
  "framework" : "Accelerate",
  "identifier" : "/documentation/Accelerate/BNNS/applyTopK(k:input:bestValues:bestIndices:axis:batchSize:filterParameters:)",
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  "title" : "applyTopK(k:input:bestValues:bestIndices:axis:batchSize:filterParameters:)"
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# applyTopK(k:input:bestValues:bestIndices:axis:batchSize:filterParameters:)

Applies a top-k filter directly to an input.

```
static func applyTopK(k: Int, input: BNNSNDArrayDescriptor, bestValues: BNNSNDArrayDescriptor, bestIndices: BNNSNDArrayDescriptor, axis: Int, batchSize: Int, filterParameters: BNNSFilterParameters? = nil) throws
```

## Parameters

`k`

The number of entries the operation finds.

`input`

The descriptor of the input.

`bestValues`

The descriptor of the k best values generated by the operation.

`bestIndices`

The descriptor of the indices of the k best values generated by the operation.

`axis`

The axis along which the operation finds top-k entries.

`batchSize`

The number of input-output pairs to process.

`filterParameters`

The filter runtime parameters.

## Discussion

> Important:
> The input data type and best values data type must be `float`, and the best indices data type must be `int32`.

## See Also

[`func BNNSDirectApplyTopK(Int, Int, Int, UnsafePointer<BNNSNDArrayDescriptor>, Int, UnsafeMutablePointer<BNNSNDArrayDescriptor>, Int, UnsafeMutablePointer<BNNSNDArrayDescriptor>?, Int, UnsafePointer<BNNSFilterParameters>?) -> Int32`](/documentation/Accelerate/BNNSDirectApplyTopK(_:_:_:_:_:_:_:_:_:_:))

Applies a top-k filter directly to an input.


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