.. _method-multilevel_sampling-qoi_aggregation-sum:

"""
sum
"""


Aggregate the variances over all QoIs to generate a target for each level in a MLMC algorithm.


.. toctree::
   :hidden:
   :maxdepth: 1



**Specification**

- *Alias:* None

- *Arguments:* None


**Description**


The variances of the ``allocation_target`` of :math:`Y^i_\ell, i = 1,...,R`  are aggregated and a single sample allocation is computed.



**Examples**


The following method block

.. code-block::

    method,
     model_pointer = 'HIERARCH'
            multilevel_sampling
       pilot_samples = 20 seed = 1237
       convergence_tolerance = .01
       allocation_target = mean
          qoi_aggregation = sum


uses the sum rule to aggregate the variance over the qois.


