separation.h

Go to the documentation of this file.

/****************************************************************************
 *   This file is part of the aGrUM/pyAgrum library.                        *
 *                                                                          *
 *   Copyright (c) 2005-2026 by                                             *
 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
 *                                                                          *
 *   The aGrUM/pyAgrum library is free software; you can redistribute it    *
 *   and/or modify it under the terms of either :                           *
 *                                                                          *
 *    - the GNU Lesser General Public License as published by               *
 *      the Free Software Foundation, either version 3 of the License,      *
 *      or (at your option) any later version,                              *
 *    - the MIT license (MIT),                                              *
 *    - or both in dual license, as here.                                   *
 *                                                                          *
 *   (see https://agrum.gitlab.io/articles/dual-licenses-lgplv3mit.html)    *
 *                                                                          *
 *   This aGrUM/pyAgrum library is distributed in the hope that it will be  *
 *   useful, but WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,          *
 *   INCLUDING BUT NOT LIMITED TO THE WARRANTIES MERCHANTABILITY or FITNESS *
 *   FOR A PARTICULAR PURPOSE  AND NONINFRINGEMENT. IN NO EVENT SHALL THE   *
 *   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER *
 *   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,        *
 *   ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR  *
 *   OTHER DEALINGS IN THE SOFTWARE.                                        *
 *                                                                          *
 *   See LICENCES for more details.                                         *
 *                                                                          *
 *   SPDX-FileCopyrightText: Copyright 2005-2026                            *
 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
 *   SPDX-License-Identifier: LGPL-3.0-or-later OR MIT                      *
 *                                                                          *
 *   Contact  : info_at_agrum_dot_org                                       *
 *   homepage : http://agrum.gitlab.io                                      *
 *   gitlab   : https://gitlab.com/agrumery/agrum                           *
 *                                                                          *
 ****************************************************************************/

 
#ifndef GUM_DSEPARATION_H
#define GUM_DSEPARATION_H
 
#include <agrum/agrum.h>
 
#include <agrum/base/graphs/DAG.h>
 
namespace gum {

  class Separation {
    public:
    // =======================================================================
    // Core public API
    // =======================================================================

    static bool isDSeparated(const DAG& dag, const NodeSet& X, const NodeSet& Y, const NodeSet& Z);

    static bool
        isBackdoorSeparated(const DAG& dag, const NodeSet& X, const NodeSet& Y, const NodeSet& Z);

    static bool
        isForwardSeparated(const DAG& dag, const NodeSet& X, const NodeSet& Y, const NodeSet& Z);
 
    // =======================================================================
    // Optional reduction for speed
    // =======================================================================

    static DAG
        reduceForDSeparation(const DAG& dag, const NodeSet& X, const NodeSet& Y, const NodeSet& Z);

    static NodeSet
        findBarrenNodes(const DAG& dag, const NodeSet& evidenceZ, const NodeSet& targetsXY);
 
    // =======================================================================
    // Minimal structural helpers (delegating to DAG where possible)
    // =======================================================================

    static bool isAncestorOf(const DAG& dag, NodeId x, NodeId y);

    static bool isDescendantOf(const DAG& dag, NodeId x, NodeId y);
 
    private:
    // =======================================================================
    // Internal helper
    // =======================================================================

    static bool anyUndirectedConnection(const UndiGraph& ug, const NodeSet& A, const NodeSet& B);
  };
 
}   // namespace gum
 
#endif   // GUM_DSEPARATION_H