get_prior

sherpa.astro.ui.get_prior(par)

Return the prior function for a parameter (MCMC).

The default behavior of the pyBLoCXS MCMC sampler (run by the get_draws function) is to use a flat prior for each parameter. The get_prior routine finds the current prior assigned to a parameter, and set_prior is used to change it.

Parameters:

para sherpa.models.parameter.Parameter instance

A parameter of a model instance.

Returns:

prior

The parameter prior set by a previous call to set_prior. This may be a function or model instance.

Raises:

ValueError

If a prior has not been set for the parameter.

See also

set_prior

Set the prior function to use with a parameter.

Examples

>>> prior = get_prior(bgnd.c0)
>>> print(prior)