Extending the fit statistic by including the R2-Statistic

[Anselmoo]

First Time Issue Code

Extending the fit statistic by including the R2-Statistic

Description

A Minimal, Complete, and Verifiable example

Could be implemented here:

https://github.com/lmfit/lmfit-py/blob/e54a44c68f9cb40836b9aca5398436f4f2b20b15/lmfit/minimizer.py#L358-L380

Version information

lmfit 1.0.3

Link(s)

Discussed in https://github.com/lmfit/lmfit-py/discussions/801