.. _method-optpp_g_newton-centering_parameter:

"""""""""""""""""""
centering_parameter
"""""""""""""""""""


Controls how closely the algorithm should follow the "central path"


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**Specification**

- *Alias:* None

- *Arguments:* REAL

- *Default:* Merit function dependent: 0.2 (el_bakry), 0.2 (argaez_tapia), 0.1 (van_shanno)


**Description**


The ``centering_parameter`` specification is a parameter (between 0 and
1) that controls how closely the algorithm should follow the "central
path".
See  :cite:p:`Wright1` for the definition of central
path. The larger the value, the more closely the algorithm follows the
central path, which results in small steps. A value of 0 indicates
that the algorithm will take a pure Newton step. Default values are
.2, .2, and .1 for the ``el_bakry``, ``argaez_tapia``, and ``van_shanno``
merit functions, respectively.