Hi,
I tried to be comprehensive but Jim's comment is indeed in place.
I have data of a practice experiment where people practice a certain motor
task and time-to-completion was recorded.
Appropriately, the time measure declines as practice goes on. And, again
appropriately, the relation seems to be non-linear. It looks like y=1/x but
much less steep.
I understand that the general case of such functions is called
power-function.
So what I'm looking for is something like abline() with a power-function fit
(rather then a linear one).
Jim is also correct writing that I would like to have separate fits for
'c'
and 'nc'.
Of course this can be achieved using subset() but, as Dennis wrote, some
graphic functions include an option to graph the data by groups.
Thanks again for any tip or reference.
dror
-------------
On Tue, Dec 29, 2009 at 10:56 PM, jim holtman <jholtman@gmail.com> wrote:
> It would help if you were more explicit on what you were trying to look
> at. I assume that you want two curves ('c' and'nc') on one
graphs and you
> can do that with the basic plot routines, or you can use the
'lattice'
> package, but without knowing what you are looking for, it is hard to tell.
>
> On Tue, Dec 29, 2009 at 3:33 PM, Dror D Lev <dror.teach@gmail.com>
wrote:
>
>> Hello,
>>
>> I have practice data of motor action in the format:
>>
>> S | Cond. | Time
>> ----+---------+--------
>> 01 | c | 1.23
>> 01 | nc | 0.89
>> 02 | c | 2.15
>> 02 | nc | 1.80
>> .....
>>
>> I want to look at the learning curves graphically.
>>
>> I will appreciate pointers to relevant functions / packages.
>>
>> Thanks in advance,
>> dror
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help@r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>>
http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>
>
> --
> Jim Holtman
> Cincinnati, OH
> +1 513 646 9390
>
> What is the problem that you are trying to solve?
>
[[alternative HTML version deleted]]