select(_:_:)

Declaration

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

Parameters

• valueIfTrue:

  The value that the operation returns when the corresponding value in self is true.

• valueIfFalse:

  The values that the operation returns when the corresponding value in self is false.

Discussion

For example, the following code returns Float.infinity when the corresponding elements in z are true and the elements in valueIfFalse 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 y = builder.argument(dataType: Float.self, shape: [8])

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

    return [ masked ]
}

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

let y = BNNSTensor.allocate(initializingFrom: [10, 20, 30, 40, 50, 60, 70, 80] as [Float],
                            shape: [8], stride: [1])

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

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

try ctx.executeFunction(arguments: &args)

// Prints "[Float.infinity, Float.infinity, 30, 40, Float.infinity, Float.infinity, 70, 80]".
print(scalar_tensor.makeArray(of: Float.self))