[R] Skipping specified rows in scan or read.table

[Abhijit Dasgupta]

Hi Ravi,

One thing I tend to do is, when using read.table, specify the option 
'colClasses='character''. This forces everything to be read as a 
character. From there, as.numeric works fine, and you don't have to deal 
with factors and reconverting them.

Hope this helps
Abhijit

Ravi Varadhan wrote:
> Hi,
>
>  
>
> I have a data file, certain lines of which are character fields.  I would
> like to skip these rows, and read the data file as a numeric data frame.  I
> know that I can skip lines at the beginning with read.table and scan, but is
> there a way to skip a specified sequence of lines (e.g., 1, 2, 10, 11, 19,
> 20, 28, 29, etc.) ?  
>
>  
>
> If I read the entire data file, and then delete the character fields, the
> values are still kept as factors, with each value denoted by its level.
> Since, I have continuous variables, there are as many levels as there are
> values.  I am unable to coerce this to "numeric" mode.  Is there a way to do
> this so that I can then manipulate the numeric data frame?
>
>  
>
> Thanks for any help.
>
> Best,
>
> Ravi.
>
> ----------------------------------------------------------------------------
> -------
>
> Ravi Varadhan, Ph.D.
>
> Assistant Professor, The Center on Aging and Health
>
> Division of Geriatric Medicine and Gerontology 
>
> Johns Hopkins University
>
> Ph: (410) 502-2619
>
> Fax: (410) 614-9625
>
> Email: rvaradhan at jhmi.edu
>
> Webpage:  http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html
>
>  
>
> ----------------------------------------------------------------------------
> --------
>
>  
>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
>