hello,all: I have met a equation like dx/dt = x + b(t) in my work. b(t) is a term that counteracts the instability of the first term in rhs, and is interpolated from experimental data. But it was found that the solution is very sensitive to the values of b(t). Can I transform x to another function to reduce the instability? Urgently! Thank you all.

ps: The problem arises in the context of the mixing model of PDF method, and I met many more problems on this aspect. Hope to discuss with all of you, if you were working on it as well.

(1). Try to reduce the dt when x gets larger.(2). It is a log function, or exponential function behavior.

Thank you, John.