<!--
{
  "availability" : [
    "iOS: 10.0.0 - 14.0.0",
    "iPadOS: 10.0.0 - 14.0.0",
    "macCatalyst: 13.1.0 - 14.0.0",
    "macOS: 10.12.0 - 11.0.0",
    "tvOS: 10.0.0 - 14.0.0",
    "visionOS: 1.0.0 - 1.0.0",
    "watchOS: 3.0.0 - 7.0.0"
  ],
  "documentType" : "symbol",
  "framework" : "Accelerate",
  "identifier" : "/documentation/Accelerate/BNNSFullyConnectedLayerParameters/init(in_size:out_size:weights:bias:activation:)",
  "metadataVersion" : "0.1.0",
  "role" : "Initializer",
  "symbol" : {
    "kind" : "Initializer",
    "modules" : [
      "Accelerate"
    ],
    "preciseIdentifier" : "s:So33BNNSFullyConnectedLayerParametersa7in_size04out_F07weights4bias10activationABSi_SiSo13BNNSLayerDataaAISo14BNNSActivationatcfc"
  },
  "title" : "init(in_size:out_size:weights:bias:activation:)"
}
-->

# init(in_size:out_size:weights:bias:activation:)

Returns a new fully connected layer parameters structure.

```
init(in_size: Int, out_size: Int, weights: BNNSLayerData, bias: BNNSLayerData, activation: BNNSActivation)
```

## Parameters

`in_size`

The size of the input vector.

`out_size`

The size of the output vector.

`weights`

Matrix coefficients, containing [`in_size`](/documentation/Accelerate/BNNSFullyConnectedLayerParameters/in_size) `*` [`out_size`](/documentation/Accelerate/BNNSFullyConnectedLayerParameters/out_size) values.

`bias`

Layer bias, containing [`out_size`](/documentation/Accelerate/BNNSFullyConnectedLayerParameters/out_size) values, one for each output component.

`activation`

The layer activation function.

## Discussion

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)