Beispiel #1
0
  /**
   * Sets the coefficient for the a->b edge to the given coefficient, if within range. Otherwise
   * does nothing.
   *
   * @param a a -> b
   * @param b a -> b
   * @param coef The coefficient of a -> b.
   * @return true if the coefficent was set (i.e. was within range), false if not.
   */
  public boolean setEdgeCoefficient(Node a, Node b, final double coef) {
    Edge edge = Edges.directedEdge(a, b);

    if (edgeParameters.get(edge) == null) {
      throw new NullPointerException("Not a coefficient parameter in this model: " + edge);
    }

    if (editingEdge == null || !edge.equals(editingEdge)) {
      range = getParameterRange(edge);
      editingEdge = edge;
    }

    if (coef > range.getLow() && coef < range.getHigh()) {
      edgeParameters.put(edge, coef);
      return true;
    }

    return false;

    //        if (!paramInBounds(edge, coef)) {
    //            edgeParameters.put(edge, d);
    //            return false;
    //        }
    //
    //        edgeParameters.put(edge, coef);
    //        return true;
  }
Beispiel #2
0
  /**
   * @param a a->b
   * @param b a->b
   * @return The coefficient for a->b.
   */
  public double getEdgeCoefficient(Node a, Node b) {
    Edge edge = Edges.directedEdge(a, b);
    Double d = edgeParameters.get(edge);

    if (d == null) {
      return Double.NaN;
      //            throw new IllegalArgumentException("Not a directed edge in this model: " +
      // edge);
    }

    return d;
  }
Beispiel #3
0
  private void ruleR1(Graph skeleton, Graph graph, List<Node> nodes) {
    for (Node node : nodes) {
      SortedMap<Double, String> scoreReports = new TreeMap<Double, String>();

      List<Node> adj = skeleton.getAdjacentNodes(node);

      DepthChoiceGenerator gen = new DepthChoiceGenerator(adj.size(), adj.size());
      int[] choice;
      double maxScore = Double.NEGATIVE_INFINITY;
      List<Node> parents = null;

      while ((choice = gen.next()) != null) {
        List<Node> _parents = GraphUtils.asList(choice, adj);

        double score = score(node, _parents);
        scoreReports.put(-score, _parents.toString());

        if (score > maxScore) {
          maxScore = score;
          parents = _parents;
        }
      }

      for (double score : scoreReports.keySet()) {
        TetradLogger.getInstance()
            .log(
                "score",
                "For " + node + " parents = " + scoreReports.get(score) + " score = " + -score);
      }

      TetradLogger.getInstance().log("score", "");

      if (parents == null) {
        continue;
      }

      if (normal(node, parents)) continue;

      for (Node _node : adj) {
        if (parents.contains(_node)) {
          Edge parentEdge = Edges.directedEdge(_node, node);

          if (!graph.containsEdge(parentEdge)) {
            graph.addEdge(parentEdge);
          }
        }
      }
    }
  }
Beispiel #4
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  private Graph pickDag(Graph graph) {
    SearchGraphUtils.basicPattern(graph, false);
    addRequiredEdges(graph);
    boolean containsUndirected;

    do {
      containsUndirected = false;

      for (Edge edge : graph.getEdges()) {
        if (Edges.isUndirectedEdge(edge)) {
          containsUndirected = true;
          graph.removeEdge(edge);
          Edge _edge = Edges.directedEdge(edge.getNode1(), edge.getNode2());
          graph.addEdge(_edge);
        }
      }

      meekOrient(graph, getKnowledge());
    } while (containsUndirected);

    return graph;
  }
Beispiel #5
0
 public ParameterRange getCoefficientRange(Node a, Node b) {
   return getParameterRange(Edges.directedEdge(a, b));
 }
Beispiel #6
0
  /**
   * Constructs a new standardized SEM IM from the freeParameters in the given SEM IM.
   *
   * @param im Stop asking me for these things! The given SEM IM!!!
   * @param initialization CALCULATE_FROM_SEM if the initial values will be calculated from the
   *     given SEM IM; INITIALIZE_FROM_DATA if data will be simulated from the given SEM,
   *     standardized, and estimated.
   */
  public StandardizedSemIm(SemIm im, Initialization initialization) {
    this.semPm = new SemPm(im.getSemPm());
    this.semGraph = new SemGraph(semPm.getGraph());
    semGraph.setShowErrorTerms(true);

    if (semGraph.existsDirectedCycle()) {
      throw new IllegalArgumentException("The cyclic case is not handled.");
    }

    if (initialization == Initialization.CALCULATE_FROM_SEM) {
      //         This code calculates the new coefficients directly from the old ones.
      edgeParameters = new HashMap<Edge, Double>();

      List<Node> nodes = im.getVariableNodes();
      TetradMatrix impliedCovar = im.getImplCovar(true);

      for (Parameter parameter : im.getSemPm().getParameters()) {
        if (parameter.getType() == ParamType.COEF) {
          Node a = parameter.getNodeA();
          Node b = parameter.getNodeB();
          int aindex = nodes.indexOf(a);
          int bindex = nodes.indexOf(b);
          double vara = impliedCovar.get(aindex, aindex);
          double stda = Math.sqrt(vara);
          double varb = impliedCovar.get(bindex, bindex);
          double stdb = Math.sqrt(varb);
          double oldCoef = im.getEdgeCoef(a, b);
          double newCoef = (stda / stdb) * oldCoef;
          edgeParameters.put(Edges.directedEdge(a, b), newCoef);
        } else if (parameter.getType() == ParamType.COVAR) {
          Node a = parameter.getNodeA();
          Node b = parameter.getNodeB();
          Node exoa = semGraph.getExogenous(a);
          Node exob = semGraph.getExogenous(b);
          double covar = im.getErrCovar(a, b) / Math.sqrt(im.getErrVar(a) * im.getErrVar(b));
          edgeParameters.put(Edges.bidirectedEdge(exoa, exob), covar);
        }
      }
    } else {

      // This code estimates the new coefficients from simulated data from the old model.
      DataSet dataSet = im.simulateData(1000, false);
      TetradMatrix _dataSet = dataSet.getDoubleData();
      _dataSet = DataUtils.standardizeData(_dataSet);
      DataSet dataSetStandardized = ColtDataSet.makeData(dataSet.getVariables(), _dataSet);

      SemEstimator estimator = new SemEstimator(dataSetStandardized, im.getSemPm());
      SemIm imStandardized = estimator.estimate();

      edgeParameters = new HashMap<Edge, Double>();

      for (Parameter parameter : imStandardized.getSemPm().getParameters()) {
        if (parameter.getType() == ParamType.COEF) {
          Node a = parameter.getNodeA();
          Node b = parameter.getNodeB();
          double coef = imStandardized.getEdgeCoef(a, b);
          edgeParameters.put(Edges.directedEdge(a, b), coef);
        } else if (parameter.getType() == ParamType.COVAR) {
          Node a = parameter.getNodeA();
          Node b = parameter.getNodeB();
          Node exoa = semGraph.getExogenous(a);
          Node exob = semGraph.getExogenous(b);
          double covar = -im.getErrCovar(a, b) / Math.sqrt(im.getErrVar(a) * im.getErrVar(b));
          edgeParameters.put(Edges.bidirectedEdge(exoa, exob), covar);
        }
      }
    }

    this.measuredNodes = Collections.unmodifiableList(semPm.getMeasuredNodes());
  }