Before we define the NeuralNetwork class, let's take a look at an example of Java code with interface:
public interface IActivationFunction {
double calc(double x);
public enum ActivationFunctionENUM {
STEP, LINEAR, SIGMOID, HYPERTAN
}
}The calc() signature method is used by a specific Activation Function that implements this interface, the Sigmoid function, for example:
public class Sigmoid implements IActivationFunction {
private double a=1.0;
public Sigmoid(double _a){this.a=_a;}
@Override
public double calc(double x){
return 1.0/(1.0+Math.exp(-a*x));
}
}This is one example of polymorphism, whereby a class or method may present different behavior, but yet under the same signature, allowing a flexible application.