[R] [FORGED] Newbie Question on R versus Matlab/Octave versus C

[Alan Feuerbacher]

On 1/28/2019 5:17 PM, Bert Gunter wrote:
> I would say your question is foolish -- you disagree no doubt! -- 
> because the point of using R (or Octave or C++) is to take advantage of 
> the packages (= "libraries" in some languages; a library is something 
> different in R) it (or they) offers to simplify your task. Many of R's 
> libraries are written in C (or Fortran) an thus **are** fast as well as 
> having task-appropriate functionality and UI's .

Yes, I'm well aware of the libraries in Octave. But so far as I was able 
to see, none of them fit my needs. I used Octave at first because I'm 
familiar with it. But far from an expert.

> So I think instead of pursuing this discussion you would do well to 
> search. I find rseek.org <http://rseek.org> to be especially good for 
> this sort of thing. Searching there on "demography" brought up what 
> appeared to be many appropriate hits -- including the "demography" 
> package! -- which you could then examine to see whether and to what 
> extent they provide the functionality you seek.

I looked over the demography package, and it indeed appears to do what I 
want. But it seems to be far more complicated than my simple problem, 
and has a large learning curve.

Alan

> Cheers,
> Bert
> 
> 
> Bert Gunter
> 
> "The trouble with having an open mind is that people keep coming along 
> and sticking things into it."
> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
> 
> 
> On Mon, Jan 28, 2019 at 4:00 PM Alan Feuerbacher <alanf00 using comcast.net 
> <mailto:alanf00 using comcast.net>> wrote:
> 
>     On 1/28/2019 4:20 PM, Rolf Turner wrote:
>      >
>      > On 1/29/19 10:05 AM, Alan Feuerbacher wrote:
>      >
>      >> Hi,
>      >>
>      >> I recently learned of the existence of R through a physicist friend
>      >> who uses it in his research. I've used Octave for a decade, and
>     C for
>      >> 35 years, but would like to learn R. These all have advantages and
>      >> disadvantages for certain tasks, but as I'm new to R I hardly
>     know how
>      >> to evaluate them. Any suggestions?
>      >
>      > * C is fast, but with a syntax that is (to my mind) virtually
>      >    incomprehensible.  (You probably think differently about this.)
> 
>     I've been doing it long enough that I have little problem with it,
>     except for pointers. :-)
> 
>      > * In C, you essentially have to roll your own for all tasks; in R,
>      >    practically anything (well ...) that you want to do has already
>      >    been programmed up.  CRAN is a wonderful resource, and there's
>     more
>      >    on github.
>       >
>      > * The syntax of R meshes beautifully with *my* thought patterns;
>     YMMV.
>      >
>      > * Why not just bog in and try R out?  It's free, it's readily
>     available,
>      >    and there are a number of good online tutorials.
> 
>     I just installed R on my Linux Fedora system, so I'll do that.
> 
>     I wonder if you'd care to comment on my little project that prompted
>     this? As part of another project, I wanted to model population growth
>     starting from a handful of starting individuals. This is exponential in
>     the long run, of course, but I wanted to see how a few basic parameters
>     affected the outcome. Using Octave, I modeled a single person as a
>     "cell", which in Octave has a good deal of overhead. The program
>     basically looped over the entire population, and updated each person
>     according to the parameters, which included random statistical
>     variations. So when the total population reached, say 10,000, and an
>     update time of 1 day, the program had to execute 10,000 x 365 update
>     operations for each year of growth. For large populations, say 100,000,
>     the program did not return even after 24 hours of run time.
> 
>     So I switched to C, and used its "struct" declaration and an array of
>     structs to model the population. This allowed the program to
>     complete in
>     under a minute as opposed to 24 hours+. So in line with your
>     comments, C
>     is far more efficient than Octave.
> 
>     How do you think R would fare in this simulation?
> 
>     Alan
> 
> 
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