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ideas, modeling highly discrete time-series data
2 messages · Mike Williamson, Kjetil Halvorsen
You could try the timeseries list at https://www.jiscmail.ac.uk/cgi-bin/webadmin?A0=TIMESERIES kjetil
On Mon, Dec 20, 2010 at 6:26 PM, Mike Williamson <this.is.mvw at gmail.com> wrote:
Hello all, ? ?First of all, thanks so those of you who helped me a week or so ago managing a time series with varying gaps between the data series in 'R'. (My final preferred solution was to use "its" function & then forecast(Arima( ) ). ?) ? ?My next question is a general statistical question where I'd like some advice, for those willing / able to proffer any wisdom: ? - I need to predict using this same time series, where the *data* are ? highly discrete. ?E.g., I will have values like 1e5, 2.2e5, and 3.6e5, but I ? will never have 1.3e5 or 1.8e5, etc. ? ? ?- I could simply leave these values as discrete, similar to a binomial ? ? ?distribution, but then I am not sure how to use time series tricks like ? ? ?arima above. ?For time-series analyses that I know of, an assumption of an ? ? ?approximately normal distribution is expected. ?No simple normalization ? ? ?(e.g., log(values) ) works, since the non-normality arises from the highly ? ? ?discrete distribution more than any drastic asymmetry in the population ? ? ?spread. ? ? ?- I could leave the values as they are an work with a model where the ? ? ?assumption is violated... I am not sure how sensitive a model such as arima ? ? ?is on the population distribution ? ? ?- Or I could... (here's where I am hoping for some collective genius). ? ?Thanks in advance for any help! ?If this isn't the best forum, since I know this is not specifically an 'R' question, please let me know of a better forum to post such a question. ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Thanks! ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Mike "Telescopes and bathyscaphes and sonar probes of Scottish lakes, Tacoma Narrows bridge collapse explained with abstract phase-space maps, Some x-ray slides, a music score, Minard's Napoleanic war: The most exciting frontier is charting what's already here." ?-- xkcd -- Help protect Wikipedia. Donate now: http://wikimediafoundation.org/wiki/Support_Wikipedia/en ? ? ? ?[[alternative HTML version deleted]]
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