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# BNNS.UnaryArithmeticLayer

A layer object that wraps a unary arithmetic filter and manages its deinitialization.

```
class UnaryArithmeticLayer
```

## Topics

### Creating a Unary Arithmetic Layer

[`convenience init?(input: BNNSNDArrayDescriptor, inputDescriptorType: BNNS.DescriptorType, output: BNNSNDArrayDescriptor, outputDescriptorType: BNNS.DescriptorType, function: BNNS.ArithmeticUnaryFunction, activation: BNNS.ActivationFunction, filterParameters: BNNSFilterParameters?)`](/documentation/Accelerate/BNNS/UnaryArithmeticLayer/init(input:inputDescriptorType:output:outputDescriptorType:function:activation:filterParameters:))

Returns a new unary arithmetic layer.

### Specifying a Unary Arithmetic Function

[`enum ArithmeticUnaryFunction`](/documentation/Accelerate/BNNS/ArithmeticUnaryFunction)

Constants that describe unary arithmetic functions.

### Specifying a Descriptor Type

[`enum DescriptorType`](/documentation/Accelerate/BNNS/DescriptorType)

Constants that describe the input and output types of an arithmetic operation.

### Applying a Unary Arithmetic Layer

[`func apply(batchSize: Int, input: BNNSNDArrayDescriptor, output: BNNSNDArrayDescriptor) throws`](/documentation/Accelerate/BNNS/UnaryArithmeticLayer/apply(batchSize:input:output:))

Applies the layer to a set of input objects, writing the result to a set of output objects.

[`func applyBackward(batchSize: Int, input: BNNSNDArrayDescriptor, output: BNNSNDArrayDescriptor, outputGradient: BNNSNDArrayDescriptor, generatingInputGradient: BNNSNDArrayDescriptor) throws`](/documentation/Accelerate/BNNS/UnaryArithmeticLayer/applyBackward(batchSize:input:output:outputGradient:generatingInputGradient:))

Applies the layer backward to generate input gradients.

## Relationships

### Inherits From

[`Layer`](/documentation/Accelerate/BNNS/Layer)

---

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