Exemplo n.º 1
0
  /**
   * @return the estimated conditional probability for the given assertion conditional on the given
   *     condition.
   */
  public double getConditionalProb(Proposition assertion, Proposition condition) {
    if (assertion.getVariableSource() != condition.getVariableSource()) {
      throw new IllegalArgumentException(
          "Assertion and condition must be " + "for the same Bayes IM.");
    }

    List<Node> assertionVars = assertion.getVariableSource().getVariables();
    List<Node> dataVars = dataSet.getVariables();

    assertionVars = GraphUtils.replaceNodes(assertionVars, dataVars);

    if (!new HashSet<Node>(assertionVars).equals(new HashSet<Node>(dataVars))) {
      throw new IllegalArgumentException(
          "Assertion variable and data variables"
              + " are either different or in a different order: "
              + "\n\tAssertion vars: "
              + assertionVars
              + "\n\tData vars: "
              + dataVars);
    }

    int[] point = new int[dims.length];
    int count1 = 0;
    int count2 = 0;
    this.missingValueCaseFound = false;

    point:
    for (int i = 0; i < numRows; i++) {
      for (int j = 0; j < dims.length; j++) {
        point[j] = dataSet.getInt(i, j);

        if (point[j] == DiscreteVariable.MISSING_VALUE) {
          continue point;
        }
      }

      if (condition.isPermissibleCombination(point)) {
        count1++;

        if (assertion.isPermissibleCombination(point)) {
          count2++;
        }
      }
    }

    return count2 / (double) count1;
  }
Exemplo n.º 2
0
  /** @return the estimated probability of the given proposition. */
  public double getProb(Proposition assertion) {
    int[] point = new int[dims.length];
    int count = 0;

    this.missingValueCaseFound = false;

    point:
    for (int i = 0; i < numRows; i++) {
      for (int j = 0; j < dims.length; j++) {
        point[j] = dataSet.getInt(i, j);

        if (point[j] == DiscreteVariable.MISSING_VALUE) {
          this.missingValueCaseFound = true;
          continue point;
        }
      }

      if (assertion.isPermissibleCombination(point)) {
        count++;
      }
    }

    return count / (double) this.numRows;
  }