select(_:_:)

Declaration

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

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))