[R] <environment: 0x000000000734f888> in object of class formula

[Prof Brian Ripley]

Did you look at the help?  ?formula has a whole section about why 
formulas have environments and what they do.

On Fri, 4 Feb 2011, Aviad Klein wrote:

> # Hi all,
>
> # I've made a function to make a formula out of a data.frame without columns
> which contain a constant value.
>
> # The function "which.constant" returns the indices of colums with constant
> values:
>
> which.constant <- function(data.frame) { # counts the number of columns in a
> data.frame which are constant
> h <- sapply(sapply(data.frame,unique),length) # count unique values
> return(as.numeric(which(h==1)))}
>
> # The function "make.formula" returns the desired formula but with an
> unwanted addition :
>
> make.formula <- function(data.frame) {
>    h <- which.constant(data.frame)
>    hh <- names(data.frame)[-h]
>    hh <- paste("~",paste(hh,collapse="+"),sep="")
>    return(as.formula(hh))}
>
> # The following structure should give an example of how it works:
>
> Data <- structure(list(cs_jail_2 = c(2L, 1L, 1L, 0L, 0L, 1L), cs_jail_3 =
> c(0L,
> 0L, 0L, 0L, 0L, 0L), cs_jail_4 = c(1L, 2L, 2L, 2L, 0L, 0L)), .Names =
> c("cs_jail_2",
> "cs_jail_3", "cs_jail_4"), row.names = c(NA, 6L), class = "data.frame")
>
> make.formula(Data)
>
> # ~cs_jail_2 + cs_jail_4
> # <environment: 0x0000000007654058>
>
> # what does this <environment ...> mean?
>
> # does it effect computation in any way? how to get read of it?

See also ?environment for how to remove (sic) it.

>
> # thank you,
>
> # Aviad
> # aviadklein.wordpress.com/
>
> 	[[alternative HTML version deleted]]

Please don't send HTML when expressly asked not to in the posting 
guide.

-- 
Brian D. Ripley,                  ripley at 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