spey.backends.default_pdf.simple_pdf.Poisson#

class spey.backends.default_pdf.simple_pdf.Poisson(signal_yields: List[float], background_yields: List[float], data: List[int])[source]#

Poisson distribution without uncertainty implementation.

\[\mathcal{L}(\mu) = \prod_{i\in{\rm bins}}{\rm Poiss}(n^i|\mu n_s^i + n_b^i)\]

where \(n_{s,b}\) are signal and background yields and \(n\) are the observations.

Parameters:

__init__(signal_yields: List[float], background_yields: List[float], data: List[int])[source]#

Methods

`__init__`(signal_yields, background_yields, data)
`asimov_negative_loglikelihood`([poi_test, ...])	Compute negative log-likelihood at fixed \(\mu\) for Asimov data.
`combine`(other, **kwargs)	A routine to combine to statistical models.
`config`([allow_negative_signal, poi_upper_bound])	Model configuration.
`expected_data`(pars, **kwargs)	Compute the expected value of the statistical model
`get_hessian_logpdf_func`([expected, data])	Currently Hessian of \(\log\mathcal{L}(\mu, \theta)\) is only used to compute variance on \(\mu\).
`get_logpdf_func`([expected, data])	Generate function to compute \(\log\mathcal{L}(\mu, \theta)\) where \(\mu\) is the parameter of interest and \(\theta\) are nuisance parameters.
`get_objective_function`([expected, data, do_grad])	Objective function i.e. negative log-likelihood, \(-\log\mathcal{L}(\mu, \theta)\).
`get_sampler`(pars)	Retreives the function to sample from.
`minimize_asimov_negative_loglikelihood`([...])	A backend specific method to minimize negative log-likelihood for Asimov data.
`minimize_negative_loglikelihood`([expected, ...])	A backend specific method to minimize negative log-likelihood.
`negative_loglikelihood`([poi_test, expected])	Backend specific method to compute negative log-likelihood for a parameter of interest \(\mu\).

Attributes

`author`	Author of the backend
`is_alive`	Returns True if at least one bin has non-zero signal yield.
`main_model`	retreive the main model distribution
`name`	Name of the backend
`spey_requires`	Spey version required for the backend
`version`	Version of the backend

spey.backends.default_pdf.simple_pdf.Poisson