///////////////////////////////////////////////////////////////////////////////
// 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, 2022 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.regression;

import edu.cmu.tetrad.data.BoxDataSet;
import edu.cmu.tetrad.data.DataSet;
import edu.cmu.tetrad.data.DoubleDataBox;
import edu.cmu.tetrad.graph.Graph;
import edu.cmu.tetrad.graph.Node;
import edu.cmu.tetrad.util.Matrix;
import edu.cmu.tetrad.util.Vector;

import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;

/**
 * Sundry utilities for regression.
 */
public class RegressionUtils {

    public static DataSet residuals(DataSet dataSet, Graph graph) {
        Regression regression = new RegressionDataset(dataSet);
        Matrix residuals = new Matrix(dataSet.getNumRows(), dataSet.getNumColumns());

        for (int i = 0; i < dataSet.getNumColumns(); i++) {
            Node target = dataSet.getVariable(i);
            Node _target = graph.getNode(target.getName());

            if (_target == null) {
                throw new IllegalArgumentException("Data variable not in graph: " + target);
            }

            Set<Node> _regressors = new HashSet<>(graph.getParents(_target));

            System.out.println("For " + target + " regressors are " + _regressors);

            List<Node> regressors = new LinkedList<>();

            for (Node node : _regressors) {
                regressors.add(dataSet.getVariable(node.getName()));
            }

            RegressionResult result = regression.regress(target, regressors);
            Vector residualsColumn = result.getResiduals();
//            residuals.viewColumn(i).assign(residualsColumn);
            residuals.assignColumn(i, residualsColumn);
        }

        return new BoxDataSet(new DoubleDataBox(residuals.toArray()), dataSet.getVariables());
    }
}



