---
title: BNNS.ActivationFunction.logSigmoid
framework: accelerate
role: symbol
role_heading: Case
path: accelerate/bnns/activationfunction/logsigmoid
---

# BNNS.ActivationFunction.logSigmoid

An activation function that returns the logarithm of the sigmoid function of its input.

## Declaration

```swift
case logSigmoid
```

## Discussion

Discussion This constant defines an activation function that returns values using the following operation: log(sigmoid(x)) The following illustrates the output that the activation function generates from inputs in the range -10...10:

## See Also

### Activation Functions

- [BNNS.ActivationFunction.abs](accelerate/bnns/activationfunction/abs.md)
- [BNNS.ActivationFunction.celu(alpha:)](accelerate/bnns/activationfunction/celu(alpha:).md)
- [BNNS.ActivationFunction.clamp(bounds:)](accelerate/bnns/activationfunction/clamp(bounds:).md)
- [BNNS.ActivationFunction.clampedLeakyRectifiedLinear(alpha:beta:)](accelerate/bnns/activationfunction/clampedleakyrectifiedlinear(alpha:beta:).md)
- [BNNS.ActivationFunction.elu(alpha:)](accelerate/bnns/activationfunction/elu(alpha:).md)
- [BNNS.ActivationFunction.geluApproximation(alpha:beta:)](accelerate/bnns/activationfunction/geluapproximation(alpha:beta:).md)
- [BNNS.ActivationFunction.geluApproximation2(alpha:beta:)](accelerate/bnns/activationfunction/geluapproximation2(alpha:beta:).md)
- [BNNS.ActivationFunction.gumbel(alpha:beta:)](accelerate/bnns/activationfunction/gumbel(alpha:beta:).md)
- [BNNS.ActivationFunction.gumbelMax(alpha:beta:)](accelerate/bnns/activationfunction/gumbelmax(alpha:beta:).md)
- [BNNS.ActivationFunction.hardShrink(alpha:)](accelerate/bnns/activationfunction/hardshrink(alpha:).md)
- [BNNS.ActivationFunction.hardSigmoid(alpha:beta:)](accelerate/bnns/activationfunction/hardsigmoid(alpha:beta:).md)
- [BNNS.ActivationFunction.hardSwish(alpha:beta:)](accelerate/bnns/activationfunction/hardswish(alpha:beta:).md)
- [BNNS.ActivationFunction.identity](accelerate/bnns/activationfunction/identity.md)
- [BNNS.ActivationFunction.leakyRectifiedLinear(alpha:)](accelerate/bnns/activationfunction/leakyrectifiedlinear(alpha:).md)
- [BNNS.ActivationFunction.linear(alpha:)](accelerate/bnns/activationfunction/linear(alpha:).md)