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  "identifier" : "/documentation/Accelerate/BNNS/ActivationFunction/scaledTanh(alpha:beta:)",
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# BNNS.ActivationFunction.scaledTanh(alpha:beta:)

An activation function that returns the scaled hyperbolic tangent of its input.

```
case scaledTanh(alpha: Float, beta: Float)
```

## Discussion

This constant defines an activation function that returns values using the following operation:

```c
alpha*tanh(x*beta)
```

Use `alpha` and `beta` to specify the scale and input multiplier:

```swift
var activation = BNNSActivation(function: .scaledTanh, 
                                alpha: 1, 
                                beta: 0.5)
```

The following illustrates the output that the activation function generates from inputs in the range `-10...10`:

![Graph that shows input values for the activation function on horizontal axis and its output values on vertical axis. ](images/com.apple.accelerate/media-3654664@2x.png)

---

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