public void addObservations(double[][] x, double[] y) throws ModelSpecificationException {
        if ((x == null) || (y == null) || (x.length != y.length)) {
            throw new ModelSpecificationException(
                  LocalizedFormats.DIMENSIONS_MISMATCH_SIMPLE,
                  (x == null) ? 0 : x.length,
                  (y == null) ? 0 : y.length);
        }
        if (x.length == 0) {  // Must be no y data either
            throw new ModelSpecificationException(
                    LocalizedFormats.NO_DATA);
        }
        if (x[0].length + 1 > x.length) {
            throw new ModelSpecificationException(
                  LocalizedFormats.NOT_ENOUGH_DATA_FOR_NUMBER_OF_PREDICTORS,
                  x.length, x[0].length);
        }
        for (int i = 0; i < x.length; i++) {
            addObservation(x[i], y[i]);
        }
    }