Jennifer,
it looks like some of the columns that you are selecting don't exist.
What is the output of str(arc) before you run the code below?
Andrew
On Thu, Apr 28, 2011 at 04:49:41PM -0700, Jennifer Wessel wrote:
> This is part of my program. I am getting an error, that I cannot figure
> out, any help would very much appreciated, thanks.
>
> # subset variables
> arc <- arc[,c("SNAP", "code", "ncode", "var", "n_total")]
> Error in `[.data.frame`(arc, , c("SNAP", "code", "ncode", :
> undefined columns selected
> arc$N_eff <- with(arc, ifelse(var > 1, n_total, var * n_total))
> Error in storage.mode(test) <- "logical" : object 'var' not found
>
> ______________________________________________
> 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.
--
Andrew Robinson
Program Manager, ACERA
Department of Mathematics and Statistics Tel: +61-3-8344-6410
University of Melbourne, VIC 3010 Australia (prefer email)
http://www.ms.unimelb.edu.au/~andrewpr Fax: +61-3-8344-4599
http://www.acera.unimelb.edu.au/
Forest Analytics with R (Springer, 2011)
http://www.ms.unimelb.edu.au/FAwR/
Introduction to Scientific Programming and Simulation using R (CRC, 2009):
http://www.ms.unimelb.edu.au/spuRs/
______________________________________________
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.
