Numerical method is based on the results of the analytical Friedman method but is more advanced.
In Numerical method firstly the Friedman calculations are made.
Then results of Friedman Method (curves E(α) and A(α) ) are optimized numerically in order to achieve the better fit between experimental and simulated curves. Internally each point of curves E(α) and A(α) is a subject of small changes, and for each change the sum of the squares of residuals is checked: is it better or worser than before. If better then new point in E(α) or A(α) is saved.
The iterations are repeated until no any numerical improvements happens.