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|    Message 1,697 of 1,954    |
|    kanny to All    |
|    Re: Estimation of N-state Hidden Markov     |
|    01 Apr 08 09:45:59    |
      XPost: comp.soft-sys.matlab, comp.dsp, sci.stat.math       XPost: comp.speech.research       From: dkanejiya@gmail.com              > > Can we estimate or design a N-state Hidden Markov Model provided we       > > have a given Pdf (probability density function) or a CDF (Cummulative       > > Density function)?       >       > Not without making more assumptions or more information. Do you know       > how your pdf evolves with time? If not, you are rather stuck as you       > really don't have much of a clue as to how your observed pdf is built up       > from the emmissions of each of your N states.       >       > Of course I can solve your problem by setting N=1.              Probably he wanted to know how to estimate or design the transition       probabilities of an HMM given observation density functions for each       of the states. That should be easier - just follow the standard HMM       training but do not re-estimate the pdfs. If the algorithm reestimates       them and u don't want to change the algo all over again, just reset       them to the original constrained values after each iteration. Now your       HMM will have the optimized transition probabilities.              I just performed the operation the other way around. Constraining the       transition probabilities and estimating the best observation       distributions. It gave better results :)              [ comp.ai is moderated ... your article may take a while to appear. ]              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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