1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

// For months the missing transfer function went unnoticed. I only realized this after failing to // build a neural network to do XOR logic. //! Option type for setting the transfer function. /// Represents which transfer function to use for evaluating neural networks. #[derive(Debug, Clone, Eq, PartialEq)] pub enum TransferFunction { /// Maps input to output directly, as if there is no transfer function. Linear, /// Outputs 1 if input is greater than 0, 0 otherwise. Threshold, /// Outputs 1 if input is greater than 0, 0 if input is equal to 0, -1 otherwise. Useful /// for simple problems and boolean logic, as it only allows three possible output values. Sign, /// A non-linear function. This function is the most general, so it should be defaulted to. Sigmoid } pub fn threshold(x: f64) -> f64 { if x > 0.0 { 1.0 } else { 0.0 } } pub fn sign(x: f64) -> f64 { if x > 0.0 { 1.0 } else if x == 0.0 { 0.0 } else { -1.0 } } pub fn sigmoid(x: f64) -> f64 { 1.0 / (1.0 + (-x).exp()) }