The odeint function in jax.experimental.ode determines the initial step size internally.
However, the returned value could be nan when the initial derivative fun(t0, y0) is
much smaller than the initial value y0. This is caused by the internal algorithm which
evaluates the function at a value ~y0/fun(t0, y0), which could be far beyond the valid range
of the function and thus returns nan.
The
odeintfunction injax.experimental.odedetermines the initial step size internally. However, the returned value could benanwhen the initial derivativefun(t0, y0)is much smaller than the initial valuey0. This is caused by the internal algorithm which evaluates the function at a value ~y0/fun(t0, y0), which could be far beyond the valid range of the function and thus returnsnan.