[R] two questions for R beginners

[Keo Ormsby]

Liviu Andronic escribió:
> On Mon, Mar 1, 2010 at 11:49 PM, Liviu Andronic <landronimirc at gmail.com> wrote:
>   
>> On 3/1/10, Keo Ormsby <keo.ormsby2 at gmail.com> wrote:
>>     
>>>  Perhaps my biggest problem was that I couldn't (and still haven't) seen
>>> *absolute beginners* documents.
>>>
>>>       
>> there was once a link posted on r-sig-teaching that would probably fit
>> your needs, but I cannot find it now.
>>
>>     
>
> OK, I found it. Below is an excerpt of that r-sig-teaching e-mail.
> Liviu
>
> On Thu, Jul 2, 2009 at 2:19 PM, Robert W. Hayden <hayden at mv.mv.com> wrote:
>   
>> I think such a website would be a real asset.  It would be most useful
>> if it either were restricted to intro. stats. OR organized so that
>> materials for real beginners were easy to extract from all the
>> materials for programmers and Ph.D. statisticians.  As a relative
>> beginner myself, I find the usual resources useless.  In self defense,
>> I created materials for my own beginning students:
>>
>>  http://courses.statistics.com/software/R/Rhome.htm
>>     
Hi Liviu,
This is indeed the best site for introduction I have seen. Although it 
still assumes some things that at first might seem unintuitive to the 
absolute beginner I talk about. For instance, in the first page, it 
shows that you can do sqrt(x), where x can be a vector, and return a 
vector of the square roots of each number. Although this is high school 
matrix algebra, most users expect that the input to square root function 
to be a single number, not a matrix, as in Excel or a calculator. Other 
concepts that are not explicitly introduced are "R workspace", the use 
of arguments in functions (with or without the "="), etc. Others are 
things like  diff(range(rainfall)) , where you have the output of one 
function used as the input to another, all in the same command line. All 
these things seem very basic, but can be difficult if you are trying to 
learn on your own with no prior experience in programming.
I hope I am not sounding too difficult and contrarian, I am just trying 
to share my experience with starting with R, and in trying to convey 
this learning to my colleagues and students. In the end, I did find 
everything I needed to learn, and now I feel at ease with R, and I 
believe that almost anybody that can use Excel or something like it, 
could learn R.

Thank you for the information,
Best wishes,
Keo.