On Mon, 20 Oct 2014 00:16:42 +0100 Patrick O'Callaghan <pocallag...@gmail.com> wrote:
> On Mon, 2014-10-20 at 08:31 +1300, Rolf Turner wrote: > > On 20/10/14 01:28, Patrick O'Callaghan wrote: > > > On Sat, 2014-10-18 at 01:10 +0000, Bill Oliver wrote: > > >> Here's the problem. Let's say you have a set of data and you want to > > >> characterize it in order to use it as the basis of a model. In order > > >> to do that, you really need to know the underlying PDF. > > > > > > I assume you mean Probability Distribution Function, not Portable > > > Document Format. That might not be clear to everyone, particularly on a > > > list such as this one. > > > > Probability *density* function, actually. :-) > > It can be either Distribution or Density. Also a few other things (see > Wikipedia). Hi, I believe that Rolf and I (and Bill O) were referencing PDFs from a probabilistic/statistical perspective. I don't quite know how Wikipedia places as a quality reference for expertise in everything (I use it more to find references for further reading), but in probability, a pdf expands to a probability density function. There is a no such thing as a probability distribution function because as noted, the term itself is ambiguous and imprecise. Precise statements (even when quantifying imprecision) are always preferred in scientific literature. Of course, some undergraduate texts also must share the blame: nowadays I have noticed that they pretty much define anything any way. (Example: many authors incorrectly call the probability mass function as a probability density function, perhaps just to be different -- but which is why you have inattentive students integrating the binomial pmf in tests and getting lost...). > That's the problem with specialist terminology where the > context isn't completely clear, e.g. we all know what ATM is when > talking about a banking network, right? (Asynchronous Transfer Mode). Or > DOS when talking about computers (Denial Of Service). I could go on. Of course, there will be confusion between Probability Density Function and Portable Document Format, because they are from different areas and hence the smiley:-) The same does not hold for the example referenced above. Sorry to be a stickler on this:-) Best wishes, Ranjan -- Important Notice: This mailbox is ignored: e-mails are set to be deleted on receipt. Please respond to the mailing list if appropriate. For those needing to send personal or professional e-mail, please use appropriate addresses. ____________________________________________________________ FREE 3D EARTH SCREENSAVER - Watch the Earth right on your desktop! Check it out at http://www.inbox.com/earth -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
