Re: forecasting result within a range

My question actually is

if there is a time series x(1), x(2), x(3), ..., x(t)

I want to predict the value of x(t+N)

but [x(1)+s(1)]<=[x(2)+s(2)]<=[x(3)+s(3)]<=...<=[x(t)+s(t)]

and [x(t)+s(t)]should always smaller or equal [x(t+1)+s(t+1)]

s(1), ..., s(t),...,s(t+n)has already known

any model I can use?

in an addition, s(1)<= s(2)<= , ..., s(t) <= s(t+n)



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