Thanks for the response! You make a really good point about the first interface -- makes it easy to use with the built in functions.
The only things that really define the process is the model (a transition matrix) and the current state. The model doesn't change but the current state does. The next state is always chosen randomly based on probabilities that come from knowing the previous state. My main argument for bundling the model and state together is that I don't want a user to pass in the wrong state or a state from a different process. Is there a Clojure opinion on these sort of things? I was thinking a third approach could be to have: (progress-state process1) -> process2 and (get-state process2) -> state so that progressing the state and getting the current state are decoupled. On Sun, Sep 14, 2014 at 6:00 AM, Jony Hudson <jonyepsi...@gmail.com> wrote: > It's nice if the function returns the same sort of data as it consumes, > because then it's easy to repeat it with `iterate` or `reduce`. So, if you > take your first example, then you could write: > > (take 100 > (iterate (partial progress-state markov-model) initial-state)) > > to get the next 100 states. > > If the process takes information at each step, e.g.: > > (progress-state-with-input markov-model-2 previous-state current-input) -> > new-state > > then you can do a similar thing with reduce: > > (take 100 > (reductions (partial progress-state-with-input markov-model-2) > initial-state inputs)) > > I'd prefer that to your second approach, as I don't think there's much > reason to bundle the process and its state. > > Another question to ponder is whether there should be a progress-state > function, or whether the model itself could be a function. If the mechanics > of the process are somewhat generic, and the `markov-model` is just data, > then it's good as it is. But I'd make sure that progress-state isn't just > an empty wrapper. > > > Jony > > On Sunday, 14 September 2014 03:28:10 UTC+1, RJ Nowling wrote: >> >> Hi all, >> >> I'm new to Clojure and implementing a Markov Model as part of a larger >> project. I'd like some advice on the API for a progress-state function. >> >> I see two possible options. In the first option, we always ask the user >> to provide and keep track of the MSM state themselves: >> >> (progress-state markov-model previous-state) -> new-state >> >> In the second approach, we create a record that combines a model and a >> current state: >> >> (defrecord MarkovProcess [model current-state]) >> >> (progress-state markov-process) -> updated-markov-process, new-state >> >> Which of these approaches is more idiomatic for Clojure? Are multiple >> return types an accepted practice in Clojure? Is there a third, better way? >> >> Thanks in advance! >> >> RJ >> > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to a topic in the > Google Groups "Clojure" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/clojure/t7th1wY-Vos/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- em rnowl...@gmail.com c 954.496.2314 -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
