---
title: "select(_:_:)"
framework: accelerate
role: symbol
role_heading: Instance Method
path: "accelerate/bnnsgraph/builder/tensor/select(_:_:)-3ha1f"
---

# select(_:_:)

Adds a tensor-scalar select operation to the current graph.

## Declaration

```swift
func select<U>(_ valueIfTrue: BNNSGraph.Builder.Tensor<U>, _ valueIfFalse: any BNNSGraph.Builder.OperationParameter<U>) -> BNNSGraph.Builder.Tensor<U> where U : BNNSScalar
```

## Parameters

- `valueIfTrue`: The values that the operation returns when the corresponding value in self is true.
- `valueIfFalse`: The value that the operation returns when the corresponding value in self is false.

## Discussion

Discussion For example, the following code returns the valueIfTrue elements when the corresponding elements in z are true and Float.infinity when the corresponding elements in z are false: let ctx = try BNNSGraph.makeContext {

builder in

let z = builder.argument(dataType: Bool.self, shape: [8])

let x = builder.argument(dataType: Float.self, shape: [8])

let masked = z.select(x, Float.infinity)

return [ masked ] }

let z = BNNSTensor.allocate(initializingFrom: [true, true, false, false,                                                true, true, false, false],                             shape: [8], stride: [1])

let x = BNNSTensor.allocate(initializingFrom: [1, 2, 3, 4, 5, 6, 7, 8] as [Float],                             shape: [8], stride: [1])

let tensor_scalar = BNNSTensor.allocateUninitialized(scalarType: Float.self, shape: [8], stride: [1])

var args = [tensor_tensor, tensor_scalar, scalar_tensor, z, x]

try ctx.executeFunction(arguments: &args)

// Prints "[1.0, 2.0, Float.infinity, Float.infinity, 5.0, 6.0, Float.infinity, Float.infinity]". print(tensor_scalar.makeArray(of: Float.self))