bayesvalidrox.bayes_inference.discrepancy.Discrepancy

class bayesvalidrox.bayes_inference.discrepancy.Discrepancy(disc_type='Gaussian', parameters=None)

Bases: object

Discrepancy class for Bayesian inference method. We define the reference or reality to be equal to what we can model and a descripancy term ( epsilon ). We consider the followin format:

$$textbf{y}_{text{reality}} = mathcal{M}(theta) + epsilon,$$

where ( epsilon in R^{N_{out}} ) represents the the effects of measurement error and model inaccuracy. For simplicity, it can be defined as an additive Gaussian disrepancy with zeromean and given covariance matrix ( Sigma ):

$$epsilon sim mathcal{N}(epsilon|0, Sigma). $$

In the context of model inversion or calibration, an observation point ( textbf{y}_i in mathcal{y} ) is a realization of a Gaussian distribution with mean value of (mathcal{M}(theta) ) and covariance matrix of ( Sigma ).

$$ p(textbf{y}|theta) = mathcal{N}(textbf{y}|mathcal{M}

(theta))$$

The following options are available:

  • Measurement uncertainty: With known redidual covariance matrix (Sigma) for

independent measurements.

Attributes

disc_typestr

Type of the noise definition. ‘Gaussian’ is only supported so far.

parametersdict or pandas.DataFrame

Known residual variance (sigma^2), i.e. diagonal entry of the covariance matrix of the multivariate normal likelihood in case of given measurement uncertainty.

__init__(disc_type='Gaussian', parameters=None)

Methods

__init__([disc_type, parameters])

build_discrepancy([measured_data])

Build used parts of the Discrepancy object.

build_discrepancy(measured_data=None)

Build used parts of the Discrepancy object.

Parameters

measured_datadict, optional

Measurements given in dictionary. This is used to set the measurement uncertainty to 0 if it is not given. The default is None.