class DeltaMeanCalculator extends Function1D<Map<Integer, ParametricVaRDataBundle>, Double> {

  @Override
  public Double evaluate(final Map<Integer, ParametricVaRDataBundle> data) {
    Validate.notNull(data, "data");
    Validate.isTrue(data.containsKey(1));
    final ParametricVaRDataBundle deltaData = data.get(1);
    final DoubleMatrix1D mean = deltaData.getExpectedReturn();
    final DoubleMatrix1D delta = (DoubleMatrix1D) deltaData.getSensitivities();
    return _algebra.getInnerProduct(delta, mean);
  }

  public  DeltaMeanCalculator(final MatrixAlgebra algebra);

}