回复 1# 的帖子
对black schole, original equation dx=r x dt + s x dz(t), difference equation:
x(n+1)-x(n)=r * x(n) *dt + s * x(n) * h * (dt)^0.5,
then x(n)=x(n+1)/ (1+r* dt + s * h * (dt)^0.5)
here h is normal distributed random number.
only personal opinion, not sure whether it is correct or not.