代码：

package dl;/*** Activator.*/public class Activator {/*** Arc tan.*/public final char ARC_TAN = 'a';/*** Elu.*/public final char ELU = 'e';/*** Gelu.*/public final char GELU = 'g';/*** Hard logistic.*/public final char HARD_LOGISTIC = 'h';/*** Identity.*/public final char IDENTITY = 'i';/*** Leaky relu, also known as parametric relu.*/public final char LEAKY_RELU = 'l';/*** Relu.*/public final char RELU = 'r';/*** Soft sign.*/public final char SOFT_SIGN = 'o';/*** Sigmoid.*/public final char SIGMOID = 's';/*** Tanh.*/public final char TANH = 't';/*** Soft plus.*/public final char SOFT_PLUS = 'u';/*** Swish.*/public final char SWISH = 'w';/*** The activator.*/private char activator;/*** Alpha for elu.*/double alpha;/*** Beta for leaky relu.*/double beta;/*** Gamma for leaky relu.*/double gamma;/************************ The first constructor.** @param paraActivator*            The activator.**********************/public Activator(char paraActivator) {activator = paraActivator;}// Of the first constructor/************************ Setter.**********************/public void setActivator(char paraActivator) {activator = paraActivator;}// Of setActivator/************************ Getter.**********************/public char getActivator() {return activator;}// Of getActivator/************************ Setter.**********************/void setAlpha(double paraAlpha) {alpha = paraAlpha;}// Of setAlpha/************************ Setter.**********************/void setBeta(double paraBeta) {beta = paraBeta;}// Of setBeta/************************ Setter.**********************/void setGamma(double paraGamma) {gamma = paraGamma;}// Of setGamma/************************ Activate according to the activation function.**********************/public double activate(double paraValue) {double resultValue = 0;switch (activator) {case ARC_TAN:resultValue = Math.atan(paraValue);break;case ELU:if (paraValue >= 0) {resultValue = paraValue;} else {resultValue = alpha * (Math.exp(paraValue) - 1);} // Of ifbreak;// case GELU:// resultValue = ?;// break;// case HARD_LOGISTIC:// resultValue = ?;// break;case IDENTITY:resultValue = paraValue;break;case LEAKY_RELU:if (paraValue >= 0) {resultValue = paraValue;} else {resultValue = alpha * paraValue;} // Of ifbreak;case SOFT_SIGN:if (paraValue >= 0) {resultValue = paraValue / (1 + paraValue);} else {resultValue = paraValue / (1 - paraValue);} // Of ifbreak;case SOFT_PLUS:resultValue = Math.log(1 + Math.exp(paraValue));break;case RELU:if (paraValue >= 0) {resultValue = paraValue;} else {resultValue = 0;} // Of ifbreak;case SIGMOID:resultValue = 1 / (1 + Math.exp(-paraValue));break;case TANH:resultValue = 2 / (1 + Math.exp(-2 * paraValue)) - 1;break;// case SWISH:// resultValue = ?;// break;default:System.out.println("Unsupported activator: " + activator);System.exit(0);}// Of switchreturn resultValue;}// Of activate/************************ Derive according to the activation function. Some use x while others use* f(x).** @param paraValue*            The original value x.* @param paraActivatedValue*            f(x).**********************/public double derive(double paraValue, double paraActivatedValue) {double resultValue = 0;switch (activator) {case ARC_TAN:resultValue = 1 / (paraValue * paraValue + 1);break;case ELU:if (paraValue >= 0) {resultValue = 1;} else {resultValue = alpha * (Math.exp(paraValue) - 1) + alpha;} // Of ifbreak;// case GELU:// resultValue = ?;// break;// case HARD_LOGISTIC:// resultValue = ?;// break;case IDENTITY:resultValue = 1;break;case LEAKY_RELU:if (paraValue >= 0) {resultValue = 1;} else {resultValue = alpha;} // Of ifbreak;case SOFT_SIGN:if (paraValue >= 0) {resultValue = 1 / (1 + paraValue) / (1 + paraValue);} else {resultValue = 1 / (1 - paraValue) / (1 - paraValue);} // Of ifbreak;case SOFT_PLUS:resultValue = 1 / (1 + Math.exp(-paraValue));break;case RELU: // Updatedif (paraValue >= 0) {resultValue = 1;} else {resultValue = 0;} // Of ifbreak;case SIGMOID: // UpdatedresultValue = paraActivatedValue * (1 - paraActivatedValue);break;case TANH: // UpdatedresultValue = 1 - paraActivatedValue * paraActivatedValue;break;// case SWISH:// resultValue = ?;// break;default:System.out.println("Unsupported activator: " + activator);System.exit(0);}// Of switchreturn resultValue;}// Of derive/************************ Overrides the method claimed in Object.**********************/public String toString() {String resultString = "Activator with function '" + activator + "'";resultString += "\r\n alpha = " + alpha + ", beta = " + beta + ", gamma = " + gamma;return resultString;}// Of toString/*********************** Test the class.*********************/public static void main(String[] args) {Activator tempActivator = new Activator('s');double tempValue = 0.6;double tempNewValue;tempNewValue = tempActivator.activate(tempValue);System.out.println("After activation: " + tempNewValue);tempNewValue = tempActivator.derive(tempValue, tempNewValue);System.out.println("After derive: " + tempNewValue);}// Of main
}// Of class Activator

结果：