code: ///////////////////////////////////////////////////////////////////////////////
  // For information as to what this class does, see the Javadoc, below.       //
  // Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,       //
  // 2007, 2008, 2009, 2010, 2014, 2015 by Peter Spirtes, Richard Scheines, Joseph   //
  // Ramsey, and Clark Glymour.                                                //
  //                                                                           //
  // This program is free software; you can redistribute it and/or modify      //
  // it under the terms of the GNU General Public License as published by      //
  // the Free Software Foundation; either version 2 of the License, or         //
  // (at your option) any later version.                                       //
  //                                                                           //
  // This program is distributed in the hope that it will be useful,           //
  // but WITHOUT ANY WARRANTY; without even the implied warranty of            //
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             //
  // GNU General Public License for more details.                              //
  //                                                                           //
  // You should have received a copy of the GNU General Public License         //
  // along with this program; if not, write to the Free Software               //
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA //
  ///////////////////////////////////////////////////////////////////////////////
  
  package edu.cmu.tetrad.bayes;
  
  import edu.cmu.tetrad.util.TetradSerializable;
  
  /**
   * Interface for a discrete Bayes updating algorithm. The main task of such and
   * algorithm is to calculate P(X = x' | evidence), where evidence takes the form
   * of a Proposition over the variables in the Bayes net, possibly with
   * additional information about which variables in the Bayes net have been
   * manipulated. Some updaters may be able to calculate joint marginals as
   * well--that is, P(AND_i{Xi = xi'} | evidence). Also, not all updaters can take
   * manipulation information into account. See implementations for details.
   *
   * @author Joseph Ramsey
   * @see Evidence
   * @see Proposition
   * @see Manipulation
   */
  public interface BayesUpdater extends TetradSerializable {
      long serialVersionUID = 23L;
  
      /**
       * @return P&lpar;variable &equals; value &vert; evidence&rpar;, where evidence is
       * getEvidence().
       */
      double getMarginal(int variable, int category);
  
      /**
       * @return true if the getJointMarginal() method is supported.
       */
      boolean isJointMarginalSupported();
  
      /**
       * @return P&lpar;variables[i] &equals; values[i] &vert; evidence&rpar;, where evidence is
       * getEvidence().
       */
      double getJointMarginal(int[] variables, int[] values);
  
      /**
       * Sets new evidence for the updater. Once this is called, old updating
       * results should not longer be available.
       */
      void setEvidence(Evidence evidence);
  
      /**
       * @return the Bayes instantiated model that is being updated.
       */
      BayesIm getBayesIm();
  
      double[] calculatePriorMarginals(int nodeIndex);
  
      double[] calculateUpdatedMarginals(int nodeIndex);
  }
  
  
  
  
  
  