This is a Mathematica file that evaluates a series of different kinetics from their differential equation form. Depending on whether doing chemistry or photochemistry this can find the concentration of products or the excitons respectively. The conditions are a typical summation of exponential decays, to profiles with a rise feature or a condition that the decay is proceeded after a spike (rise = decay time-constant).

I think it is a bit messy but I hope I get some spare time to organize this and comments even more thoroughly. Meanwhile I hope it can be of any assitance or help.