Hi,

On Jul 31, 2009, at 7:17 PM, Noah Silverman wrote:

Hello,

I'm trying to duplicate what's an easy process in RapidMiner.

In RM, we can simply use two operators:
    subgroup iteration
attribute value selection (Can use a regex for the attrribute name.)

I can do this in R with a lot of code and manual steps.  It would be
really nice to find a more automated way.

My data looks like this

group   group_height    group_weight    height  weight
g22     3.2     8.896   3.2     8.896
g22     2.5     6.95    2.5     6.95
g22     3.1     8.618   3.1     8.618
g49     2.4     6.672   2.4     6.672
g49     4.2     11.676  4.2     11.676
g49     2.5     6.95    2.5     6.95
g55     2.6     7.228   2.6     7.228
g55     3.4     9.452   3.4     9.452
g55     3.3     9.174   3.3     9.174

What I want to do is scale the data by each group
So in pseudo-code
    for(group in groups){
        if(column_name = regex(group_.*)){
            data[column_name] = scale(data[group,column_name])
        }
    }

This way I get "group wise" normalization of my data, but still have the original values which I will normailze "database wide" for some comparisons.

Can anybody help solve this one?

-N


You can do this quite easily.

Just take what you learned from the last example re: scaling subsets, and play around with some of the functions you see in the ?grep help page. You'll be using those functions against the strings you get back from colnames(data).

-steve

--
Steve Lianoglou
Graduate Student: Computational Systems Biology
  |  Memorial Sloan-Kettering Cancer Center
  |  Weill Medical College of Cornell University
Contact Info: http://cbio.mskcc.org/~lianos/contact

______________________________________________
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
and provide commented, minimal, self-contained, reproducible code.

Reply via email to