Hello, I am a new user of Mathematica, and I have the folowing question.
I am solving a system of ODEs numerically with NDSolve, the independent variable being time (t), and I would like to change a parameter during the time course. E.g., for a particular parameter {p - > 0.9} I would like to set it to 1.0 if 200 < t <= 500 and for t > 500 reset it to 0.9. How can this be done? I have tried with WhenEvent but I didnt succeed.
Thanks a lot in advance, Christian