From: Patrick Burns <pburns_at_pburns.seanet.com>

Date: Fri 02 Dec 2005 - 22:11:12 EST

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Dec 02 22:27:29 2005

Date: Fri 02 Dec 2005 - 22:11:12 EST

The key things here are:

- a data frame is a list with some attributes (unlike a matrix which is (generally) an atomic vector with attributes).
- 'as.vector' removes attributes.

Patrick Burns

patrick@burns-stat.com

+44 (0)20 8525 0696

http://www.burns-stat.com

(home of S Poetry and "A Guide for the Unwilling S User")

Robin Hankin wrote:

*>Hi
**>
*

>look at the following session, in which I have a dataframe,

*>and I want to extract the second row, without the first column.
**>
**>Everything works as expected until the last line, where I set
**>the names of x to NULL, and get a non-desired object (I
**>want c(4,3).).
**>
**>
**>Three questions:
**>
**>(1) why is as.vector(a[2,-1]) not a vector?
**>
**>(2) How come setting names to NULL gives me bad weirdness?
**>
**>(3) Can I structure my dataframe in a better way, so that
**>this problem does not occur?
**>
**>
**>
**>
**> > a <- data.frame(male=c(T,T,F),mass=c(1,4,3),height=c(4,3,2))
**> > a
**> male mass height
**>1 TRUE 1 4
**>2 TRUE 4 3
**>3 FALSE 3 2
**> > x <- as.vector(a[2,-1])
**> > x
**> mass height
**>2 4 3
**> > names(x) <- NULL
**> > x
**> structure("4", class = "AsIs") structure("3", class = "AsIs")
**>2 4 3
**> >
**>
**>--
**>Robin Hankin
**>Uncertainty Analyst
**>National Oceanography Centre, Southampton
**>European Way, Southampton SO14 3ZH, UK
**> tel 023-8059-7743
**>
**>______________________________________________
**>R-help@stat.math.ethz.ch mailing list
**>https://stat.ethz.ch/mailman/listinfo/r-help
**>PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
**>
**>
**>
**>
**>
*

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Dec 02 22:27:29 2005

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