R help - May 2010 - Objective: to create a Joint Probability Table and save as a csv file (with headers).Input: A csv file (with headers) containing raw data, arranged by columns.Variable: number of bins for each column of data, default to 5 bins per column.Data

Hi Roscoe,
I couldn't make it though that excel worksheet without my eyes glazing
over... but do you want something like

data(mtcars)
tab <- xtabs(~cyl + gear, data=mtcars)
tab/sum(tab)

?

Best,
Isat

On Mon, May 3, 2010 at 10:08 PM, Roscoe <Roscoe at exemail.com.au>
wrote:
> Dear R-Help,
>
> First post, be gentle...
>
> I am new to R: I can perform basic functions using R code - import and
> export data, load packages and not much else at this stage.
>
> Objective: to create a Joint Probability Table and save as a csv file
> (with headers).
>
> Input: A csv file (with headers) containing raw data, arranged by
> columns.
>
> Variable: number of bins for each column of data, default to 5 bins
> per column.
>
> Data import and export in R I can do, however I am a complete n00b at
> this type of statistical processing and I would really appreciate some
> guidance please.
>
> I want to take the input data and create, as final output, a Joint
> Probability Table. I can do this manually in Excel, however I am
> hoping that there is a better and more repeatable way to do so in R.
>
> An example of the steps taken is available in an Excel spreadsheet at
> http://parametricplanet.com/rvince/ScenariosExample.xls
>
> Is what I am attempting to do covered by some available function(s) or
> package(s) in R? After spending a while searching the manual and the
> various on-line help pages for ?Joint Probability Table ?I am
> beginning to suspect that it may not be, but my lack of experience in
> both stats and R could well mean that I am missing the clues.
>
> Thanks in advance.
>
>
> --
> Warm regards,
> ?Ross Bond ? ? ? ? ? ? ? ? ? ? ? ? ?mail to: Roscoe at Exemail.com.au
> ?Bundaberg, Qld
> ?Australia
>
> ______________________________________________
> R-help at 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
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Ista Zahn
Graduate student
University of Rochester
Department of Clinical and Social Psychology
http://yourpsyche.org

G'Day Ista,

Tuesday, May 4, 2010, 3:20:37 PM, you wrote:
> I couldn't make it though that excel worksheet without my eyes
> glazing over...
Heh, yeah, it is a bit long-winded. Essentially you take the input
data and run it through those steps to produce the JPT at the end.

Part of it is the odometric ordering of the data.
> but do you want something like
> data(mtcars)
> tab <- xtabs(~cyl + gear, data=mtcars)
> tab/sum(tab)
I don't think so, at least not exactly, but if I can get my head
around what that code does it might actually be doing what I want.

Thanks for that, I will attempt to break the R code down into chunks
that I can understand and go from there.


-- 
Kind regards,
 Roscoe                          mail to: Roscoe at Exemail.com.au