I’m using Rodas3() to solve a stiff ODEs in Julia. du/dt = F(u). The Analytical expression of u should be positive. However, when I use julia to solve the ODE, u may be less equal 0. I suspect that the time step was too large.
I wonder if there is parameters. When solving ODE, if the u of a certain step size is less than 0, the step size will be recalculated by rolling it back.
Thany you!