Ejemplo n.º 1
0
  private String reportIfContinuous(Graph dag, DataSet dataSet) {
    SemPm semPm = new SemPm(dag);

    SemEstimator estimator = new SemEstimator(dataSet, semPm);
    estimator.estimate();
    SemIm semIm = estimator.getEstimatedSem();

    NumberFormat nf = NumberFormat.getInstance();
    nf.setMaximumFractionDigits(4);

    StringBuilder buf = new StringBuilder();
    buf.append("\nDegrees of Freedom = ")
        .append(semPm.getDof())
        .append("Chi-Square = ")
        .append(nf.format(semIm.getChiSquare()))
        .append("\nP Value = ")
        .append(nf.format(semIm.getPValue()))
        .append("\nBIC Score = ")
        .append(nf.format(semIm.getBicScore()));

    buf.append(
        "\n\nThe above chi square test assumes that the maximum "
            + "likelihood function over the measured variables has been "
            + "maximized. Under that assumption, the null hypothesis for "
            + "the test is that the population covariance matrix over all "
            + "of the measured variables is equal to the estimated covariance "
            + "matrix over all of the measured variables written as a function "
            + "of the free model parameters--that is, the unfixed parameters "
            + "for each directed edge (the linear coefficient for that edge), "
            + "each exogenous variable (the variance for the error term for "
            + "that variable), and each bidirected edge (the covariance for "
            + "the exogenous variables it connects).  The model is explained "
            + "in Bollen, Structural Equations with Latent Variable, 110. ");

    return buf.toString();
  }