Alternative for acroread (Adobe Reader) in LINUX?

Bill Oliver vendor at billoblog.com
Sat Oct 18 00:21:35 UTC 2014


On Sat, 18 Oct 2014, Rolf Turner wrote:

>
> It would be a bit of work, although not an overwhelming intellectual 
> challenge, to produce an R package that would do essentially the same thing 
> as "easyfit".  There are a number of questions that would have to be 
> addressed of course.  E.g. just how do you want/expect the distributions to 
> be fitted to the data?  Maximum likelihood?  Are all the distributions dealt 
> with by "easyfit" amenable to being fitted via maximum likelihood?  And how 
> is the choice of distribution to be made?
> AIC?  The "easyfit" web page refers to "goodness of fit tests", which can be 
> problematic, or "visual inspection" --- always a good idea, but it too can be 
> problematic.
>
> Overall I don't think this "press a button and let the software do your 
> thinking for you" is the right way to go.  If the results matter at all, you 
> need to know what you are doing and what pitfalls can lurk to trap the 
> unwary.
>
> I don't understand what you mean by "All the R packages I've seen make you 
> build your own library of probability density functions and then do the 
> fitting on each one."  R has a large number of built-in probability density 
> functions (including *most* of the distributions listed on the "easyfit" web 
> page) and most of these can be fitted (via maximum likelihood) using the 
> fitdistr() function from the MASS package.  The fitdistr() function can fit 
> essentially any distribution for which a probability density function can be 
> written.  Goodness of fit testing is more problematic, but then as I said 
> that is a problematic topic.
> Superimposing fitted pdf-s on a histogram of the data for "visual comparison" 
> is straightforward.
>
> cheers,
>
> Rolf Turner
>

What I mean is that R has the capability of generating PDFs, and R has
the capability of calculating various goodness of fit measures, but if
you want to check goodness of fit measures against, say, 50 PDFs, then
you have to write the package.  It's easier for me to use easyfit than
write the package.

This really isn't an issue of "press a button and let the software do
your thinking," it's more like "press a button and calculate 200 distance
measures."  There's no particular virtue in doing the same thing 50
times, one by one.

billo


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