Hi all !

I would like to integrate this equation, to check if the values I get by numerical simulation are correct. My initial condition is $\displaystyle e(0)=0$ and I would like to check other values.

However, I don't know how to deal with the max function so I can't compute the exact solution.

$\displaystyle \frac{\partial e}{\partial t} = \frac{1}{\eta }max(0,\sigma-\sigma^*) $ with $\displaystyle \sigma=1-e^{-4t}$

In my specific case, I set the parameters to $\displaystyle \eta = 1/4 $, $\displaystyle \sigma^* = 1/2 $

Thank you very much for your help !