Determine the uncertainty of the returned values

[jrsmith3]

Overview

The values returned by the calculators in this package have some uncertainty. I suspect the uncertainty is limited by the uncertainty of the physical constants (Boltzmann's constant, Planck's constant, etc.), but I would like to ensure that is the case.

Deliverables

• Demonstrate the uncertainty of the returned values of the ibei.BEI methods are limited by the uncertainties of the physical constants and not by any algorithmic uncertainty.
• Include the uncertainties in the documentation and the docstrings of the package.

Related issues

• Relates to Demonstrate that the methods are returning the correct values #91.