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.search;
  
  import edu.cmu.tetrad.data.DataModel;
  import edu.cmu.tetrad.data.DataSet;
  import edu.cmu.tetrad.data.ICovarianceMatrix;
  import edu.cmu.tetrad.graph.Node;
  import edu.cmu.tetrad.util.TetradMatrix;
  
  import java.util.List;
  
  /**
   * Interface implemented by classes that do conditional independence testing. These classes are capable of serving as
   * conditional independence "oracles" for constraint-based searches.
   *
   * @author Don Crimbchin (djc2@andrew.cmu.edu)
   * @author Joseph Ramsey
   */
  public interface IndependenceTest {
  
      /**
       * @return an Independence test for a subset of the variables.
       */
      IndependenceTest indTestSubset(List<Node> vars);
  
      /**
       * @return true if the given independence question is judged true, false if not. The independence question is of the
       * form x _||_ y | z, z = <z1,...,zn>, where x, y, z1,...,zn are variables in the list returned by
       * getVariableNames().
       */
      boolean isIndependent(Node x, Node y, List<Node> z);
  
      /**
       * @return true if the given independence question is judged true, false if not. The independence question is of the
       * form x _||_ y | z, z = <z1,...,zn>, where x, y, z1,...,zn are variables in the list returned by
       * getVariableNames().
       */
      boolean isIndependent(Node x, Node y, Node... z);
  
      /**
       * @return true if the given independence question is judged false, true if not. The independence question is of the
       * form x _||_ y | z, z = <z1,...,zn>, where x, y, z1,...,zn are variables in the list returned by
       * getVariableNames().
       */
      boolean isDependent(Node x, Node y, List<Node> z);
  
      /**
       * @return true if the given independence question is judged false, true if not. The independence question is of the
       * form x _||_ y | z, z = <z1,...,zn>, where x, y, z1,...,zn are variables in the list returned by
       * getVariableNames().
       */
      boolean isDependent(Node x, Node y, Node... z);
  
      /**
       * @return the probability associated with the most recently executed independence test, of Double.NaN if p value is
       * not meaningful for tis test.
       */
      double getPValue();
  
      /**
       * @return the list of variables over which this independence checker is capable of determinining independence
       * relations.
       */
      List<Node> getVariables();
  
      /**
       * @return the variable by the given name.
       */
      Node getVariable(String name);
  
      /**
       * @return the list of names for the variables in getNodesInEvidence.
       */
      List<String> getVariableNames();
  
      /**
       * @return true if y is determined the variable in z.
       */
      boolean determines(List<Node> z, Node y);
  
      /**
       * @return the significance level of the independence test.
       * @throws UnsupportedOperationException if there is no significance level.
       */
      double getAlpha();
  
      /**
       * Sets the significance level.
       */
      void setAlpha(double alpha);
  
      /**
       * @return The data model for the independence test.
       */
      DataModel getData();
  
      ICovarianceMatrix getCov();
  
      List<DataSet> getDataSets();
  
      int getSampleSize();
  
      List<TetradMatrix> getCovMatrices();
  
      /**
       * A score that is higher with more likely models.
       */
      double getScore();
  
      void setVerbose(boolean verbose);
  
      boolean isVerbose();
  
  }
  
  
  
  
  