How to use an external dataset?
===============================

Two options

  * :ref:`simple_likelihood`

  * :ref:`generic_likelihood`



..  _simple_likelihood:

From ini file with the existing cosmological functions
-------------------------------------------------------

If you want to use external data with an existing ``SimpleMC`` model, you can set it in the ``ini file`` using ``h``, ``fs8`` or ``distance_mod`` cosmological functions in the key ``fn``:

.. code-block:: bash

	[custom]
	...

	model = LCDM

	datasets = generic
	path_to_data = path-to-data
	path_to_cov = path-to-data-cov
	fn = distance_mod
	...

..  _generic_likelihood:


Without cosmological functions
-------------------------------

In this case, we need to make a Python script instead to use the ``ini file`` and combine the  `simple model independent of any cosmology <simple_model.html#simple-model-independent-of-any-cosmology>`_ with new data

.. code-block:: python

    m = Parameter("m", 0, 0.05, (0, 0.1), "m_0")
    b = Parameter("b", 3, 0.05, (0, 5), "b_0")

    # create a list with your parameters objects
    parameterlist = [m, b]

    my_model = 'm*x+b'

    analyzer = DriverMC(model='simple', datasets='generic', analyzername='mcmc',
                        custom_parameters=parameterlist, custom_function=my_model, 
                        path_to_data='path-to-data', path_to_cov='path_to_data_cov',
                        fn='generic')

    analyzer.executer(nsamp=1000)