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.data;
  
  import edu.cmu.tetrad.graph.Node;
  import edu.cmu.tetrad.util.TetradMatrix;
  import edu.cmu.tetrad.util.TetradSerializable;
  
  import java.util.List;
  
  /**
   * Interface for covariance matrices. Implemented in different ways.
   * See implementations.
   */
  public interface ICovarianceMatrix extends DataModel, TetradSerializable {
      List<Node> getVariables();
  
      List<String> getVariableNames();
  
      String getVariableName(int index);
  
      int getDimension();
  
      int getSampleSize();
  
      String getName();
  
      void setName(String name);
  
      IKnowledge getKnowledge();
  
      void setKnowledge(IKnowledge knowledge);
  
      ICovarianceMatrix getSubmatrix(int[] indices);
  
      ICovarianceMatrix getSubmatrix(List<String> submatrixVarNames);
  
      ICovarianceMatrix getSubmatrix(String[] submatrixVarNames);
  
      double getValue(int i, int j);
  
      void setMatrix(TetradMatrix matrix);
  
      void setSampleSize(int sampleSize);
  
      int getSize();
  
      TetradMatrix getMatrix();
  
      void select(Node variable);
  
      void clearSelection();
  
      boolean isSelected(Node variable);
  
      List<String> getSelectedVariableNames();
  
      String toString();
  
      Node getVariable(String name);
  
      void setValue(int i, int j, double v);
  
      void removeVariables(List<String> remaining);
  
      void setVariables(List<Node> variables);
  
      TetradMatrix getSelection(int[] rows, int[] cols);
  }
  
  
  
  