def a_d(t0, u_, k):
r = u_[:3]
v = u_[3:]
# Change sign of beta with the out-of-plane velocity
beta_ = beta(t0, V_0, f, beta_0_) * np.sign(r[0] * (inc_f - inc_0))
t_ = v / norm(v)
w_ = cross(r, v) / norm(cross(r, v))
accel_v = f * (np.cos(beta_) * t_ + np.sin(beta_) * w_)
return accel_v
def a_d(t0, u_, k):
r = u_[:3]
v = u_[3:]
# Change sign of beta with the out-of-plane velocity
beta_ = beta(t0, V_0=V_0, f=f, beta_0=beta_0_) * np.sign(r[0] * (inc_f - inc_0))
t_ = v / norm(v)
w_ = cross(r, v) / norm(cross(r, v))
# n_ = cross(t_, w_)
accel_v = f * (np.cos(beta_) * t_ + np.sin(beta_) * w_)
return accel_v