package Neuro;

import java.util.Vector;
import java.util.Enumeration;

/**
 * A neuron with it's input. This class is private within the package.
 * @see NeuronalNetwork
 */
class Neuron extends NeuronalElement
{
  private int number = 0;
  private Vector inputs = null;
  private Vector signums = null;

  public Neuron( int number ) throws NeuroException
  {
    if ( number < 1 )
      throw new NeuroException( "neuron number must be >= 1" );

    this.number = number;
    inputs = new Vector();
    signums = new Vector();
  }

  public void addSubelement( NeuronalElement el, int signum ) throws NeuroException
  {
    if ( !( signum == 1 || signum == -1 ) )
      throw new NeuroException( "signum must be -1 or 1" );

    inputs.add( el );
    signums.add( new Integer( signum ) );
  }

  public int value() throws NeuroException
  {
    int ret = 0;
    if ( inputs.isEmpty() )
      throw new NeuroException( "neuron " + number + " has no input" );

    Enumeration i = inputs.elements();
    Enumeration s = signums.elements();

    while ( i.hasMoreElements() )
    {
      ret += ( (NeuronalElement) i.nextElement() ).value() * ( (Integer) s.nextElement() ).intValue();
    }

    return ( ret >= 1 )?1:0;
  }
}