SGD

public typealias Model = Model

public var learningRate: Float

public var momentum: Float

public var decay: Float

public var nesterov: Bool

public var velocity: Model.TangentVector

public var step: Int

public init(
  for model: __shared Model,
  learningRate: Float = 0.01,
  momentum: Float = 0,
  decay: Float = 0,
  nesterov: Bool = false
)

public func update(_ model: inout Model, along direction: Model.TangentVector)

public required init(copying other: SGD, to device: Device)