ParameterScaleMatrix

class sherpa.sim.sample.ParameterScaleMatrix[source] [edit on github]

Bases: ParameterScale

Correlated errors for the parameters.

Attributes Summary

sigma

Methods Summary

get_scales(fit[, myscales])

Return the samples.

Attributes Documentation

sigma: float = 1

Methods Documentation

get_scales(fit: Fit, myscales: ndarray | None = None) → ndarray[source] [edit on github]

Return the samples.

Parameters:

fit (sherpa.fit.Fit instance) – This defines the thawed parameters that are used to generate the samples, along with any possible error analysis.
myscales (numpy array or None, optional) – The scales to use: the two-dimensional covariance matrix for the parameters. If None then they are calculated from the fit, using the object’s sigma attribute to scale the results.

Returns:

scales – Two-dimensional square array of side npar, where npar is the number of free parameters in the fit. The values are the covariance matrix for the free parameters, scaled by the sigma value (or the input values if myscales is not None).

Return type:

numpy array