Estimating probability of next state (time t+1)

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asutosh

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Sep 12, 2012, 7:12:19 AM9/12/12
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Given a model and observation sequence till time t, how do i compute the probability of next state(s) time t+1 (, t+2 and so on...)?
Does Jahmm library provide this function. If not, can anyone show me how to implement this.
 
 
regards
asutosh

Sadegh Dorri N.

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Sep 19, 2012, 8:03:41 AM9/19/12
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Asutosh,

You should first learn an HMM by using the BaumWelch algorithm
(be.ac.ulg.montefiore.run.jahmm.learn.BaumWelchLearner.learn()
or
be.ac.ulg.montefiore.run.jahmm.learn.BaumWelchScaledLearner.learn())

with your observation sequence. Then use the learned HMM to calculate
the probability of the sequence in the learned HMM (Hmm.probability())
and divide it by the probability of the sequence plus the observation
you
want to calculate its probability. If you use scaling, you should use
Hmm.lnProbability() and subtract the probabilities then exponentiate
the result.

Regards,
Sadegh
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Sadegh Dorri N.

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Sep 19, 2012, 8:04:35 AM9/19/12
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Of course, if you have the model, the learning step is not required.

On Wed 12 Sep 2012 03:42:19 PM IRDT, asutosh wrote:
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