.. _method-coliny_solis_wets-expand_after_success:

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expand_after_success
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Set the factor by which a search pattern can be expanded


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**Specification**

- *Alias:* None

- *Arguments:* INTEGER

- *Default:* 5


**Description**


In general, pattern search methods can expand and contract their step
lengths.  SCOLIB pattern search methods contract the step length by
the value ``contraction_factor``, and they expand the step length by
the value (1/contraction_factor).  The ``expand_after_success`` control
specifies how many successful objective function improvements must
occur with a specific step length prior to expansion of the step
length, whereas the ``no_expansion`` flag instructs the algorithm to
forgo pattern expansion altogether.


