.. _method-bayes_calibration-queso-chain_samples:

"""""""""""""
chain_samples
"""""""""""""


Number of Markov Chain Monte Carlo posterior samples


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



**Specification**

- *Alias:* samples 

- *Arguments:* INTEGER

- *Default:* method-dependent


**Description**


The ``chain_samples`` keyword indicates the number of draws from the
posterior distribution to perform.  When an emulator is active, this
will be the number of samples on the constructed surrogate model.

*Default Behavior*

The default number of chain samples is method-dependent.  QUESO and MUQ
methods use 1000.  DREAM uses (number of generations) x (number of
chains), resulting in chain_samples close to that specified.

*Usage Tips*

MCMC methods typically require a large number of chain samples to
converge, often thousands to millions.



**Examples**



.. code-block::

    method
      bayes_calibration queso
        chain_samples = 20000




