package umontreal.iro.lecuyer.randvar;
import umontreal.iro.lecuyer.rng.*;
import umontreal.iro.lecuyer.probdist.*;


@Deprecated
/**
 * This class has been replaced by {@link GumbelGen}.
 * 
 * 

 * This class implements random variate generators for the Gumbel
 * (or extreme value) distribution. Its density is
 * 

 * 
 * 

 * f (x) = λe-e-λ(x-α)-λ(x-α)
 * 

 * where λ > 0.
 * 
 * 

 * The (non-static) nextDouble method simply calls inverseF on the
 * distribution.
 * 
 */
public class ExtremeValueGen extends RandomVariateGen  {
   protected double alpha = -1.0;
   protected double lambda = -1.0;




   /**
    * Creates an extreme value random variate generator with
    *  parameters α = alpha and λ = lambda,
    *  using stream s.
    * 
    */
   public ExtremeValueGen (RandomStream s, double alpha, double lambda)  {
      super (s, new ExtremeValueDist(alpha, lambda));
      setParams (alpha, lambda);
   }


   /**
    * Creates an extreme value random variate generator with
    *  parameters 
    * α = 0 and 
    * λ = 1, using stream s.
    * 
    */
   public ExtremeValueGen (RandomStream s)  {
      this (s, 0.0, 1.0);
   }


   /**
    * Creates a new generator object for distribution dist and
    *    stream s.
    * 
    */
   public ExtremeValueGen (RandomStream s, ExtremeValueDist dist)  {
      super (s, dist);
      if (dist != null)
         setParams (dist.getAlpha(), dist.getLambda());
   }


   /**
    * Uses inversion to generate a new variate from the extreme value
    *   distribution with parameters α = alpha and λ = lambda, using stream s.
    * 
    */
   public static double nextDouble (RandomStream s, double alpha,
                                    double lambda)  {
      return ExtremeValueDist.inverseF (alpha, lambda, s.nextDouble());
   }


   /**
    * Returns the parameter α of this object.
    * 
    */
   public double getAlpha() {
      return alpha;
   }


   /**
    * Returns the parameter λ of this object.
    * 
    * 
    */
   public double getLambda() {
      return lambda;
   }


   /**
    * Sets the parameter α and λ of this object.
    * 
    */
   protected void setParams (double alpha, double lambda) {
      if (lambda <= 0.0)
         throw new IllegalArgumentException ("lambda <= 0");
      this.lambda = lambda;
      this.alpha = alpha;
   }

}