.. _method-multilevel_blue-solution_mode-online_pilot-relaxation-fixed_factor:

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fixed_factor
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For under-relaxation of shared sample increments, apply a fixed factor that is invariant with iteration



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



**Specification**

- *Alias:* None

- *Arguments:* REAL


**Description**


When initial correlation / covariance approximations are inaccurate,
iterated sample updates can be overly aggressive, such that it becomes
advisable to only accept a portion of this suggested increment through
use of an under-relaxation factor.

In the ``fixed_factor`` option, a single relaxation factor is
specified for use on all online iterations.

**Usage Tips**

Even through the under-relaxation factor does not decay to a value of
1, the sample increments will generally decay toward an integer
truncation of zero, terminating the online iteration.

As for other relaxation specification options, the one case where the
relaxation factor will be automatically advanced to 1 is the case
where a ``max_iterations`` constraint will force early termination of
the iteration.  This advancement avoids polluting the final results
with an anticipated variance reduction that was not fully realized due
to increment throttling.

This option is equivalent to a ``factor_sequence`` specification with
a single value.




**Examples**



.. code-block::

    method,
	multilevel_blue
	  solution_mode  online_pilot
	    relaxation fixed_factor = .8
	  pilot_samples = 25
	  seed = 8674132
	  max_function_evaluations = 500