[R-sig-DB] data frame remove column

[Prof Brian Ripley]

This is off-topic for this list.  Please use R-help.

The list moderator.

On 25/08/2012 00:10, Kate Dresh wrote:
> *Hi all,*
>
>
>
> I'm trying to filter a file through the columns. This file below is a
> example of my data frame. My true data frame has seven hundred thousand
> columns and 500 hundred lines. I need to identify and to remove all columns
> that all elements equal a number 1. In this my case, columns were deleted
> are number 1,5 and 10.
>
>
>
>
>
> file <-read.table(text="
>
> 1  0  2  2  1  1  5  1  1  1
>
> 1  0  2  2  1  1  5  1  1  1
>
> 1  0  2  2  1  2  5  2  2  1
>
> 1  0  2  2  1 1  5  1  1  1
>
> 1  0 2  2   1  0  5  0  2  1
>
> 1  0  2 2   1  1  5  1  0  1
>
> ",sep="",header=FALSE)
>
>
>
> the result after the filter will be
>
>
>
> 0  2  2  1  5  1  1
>
>   0  2  2  1  5  1  1
>
>   0  2  2  2  5  2  2
>
>   0  2  2  1  5  1  1
>
>   0  2  2  0  5  0  2
>
>   0  2  2  1  5  1  0
>
>
>
>   I used this commands idlength<-sapply(file,function(x) length(unique(x))
> ),
>
> but came an error message:
>
>
>
> caught segfault ***
>
> address 0x4, cause 'memory not mapped'
>
>
>
> *My question: is it possible to remove the all columns from above file
> to *achieve* the desired result?*
>
> * *
>
> * *
>
> *Thank you for help*
>
>
>
>   Kate
>
> 	[[alternative HTML version deleted]]
>
> _______________________________________________
> R-sig-DB mailing list -- R Special Interest Group
> R-sig-DB using r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-db
>


-- 
Brian D. Ripley,                  ripley using stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595