[R] ls() and classes

[Henrik Bengtsson]

> library(R.oo)
> example(data.frame)
> example(matrix)
> example(iris)
> ll()
   member data.class dimension objectSize
1  author  character         1        120
2       d data.frame   c(10,3)       1136
3     d.0 data.frame    c(0,3)        824
4      d0 data.frame   c(10,0)        320
5     d00 data.frame    c(0,0)        312
6      dd data.frame   c(10,4)       1680
7    dni3       list         3        392
8      ii data.frame  c(150,5)       6424
9      L3  character         3        136
10   mdat     matrix    c(2,3)        480

> subset(ll(), data.class == "data.frame")
  member data.class dimension objectSize
2      d data.frame   c(10,3)       1136
3    d.0 data.frame    c(0,3)        824
4     d0 data.frame   c(10,0)        320
5    d00 data.frame    c(0,0)        312
6     dd data.frame   c(10,4)       1680
8     ii data.frame  c(150,5)       6424

> subset(ll(), data.class %in% c("character", "matrix") & objectSize > 125)
   member data.class dimension objectSize
9      L3  character         3        136
10   mdat     matrix    c(2,3)        480

You can also add your own column annotations given some rules of yours
by passing special functions.  See help(ll) for more details.

/Henrik

On Wed, Mar 19, 2008 at 7:50 AM, David Winsemius <dwinsemius at comcast.net> wrote:
> Rolf Turner <r.turner at auckland.ac.nz> wrote in
>  news:72856D72-D960-48ED-AA77-ABD353548C08 at auckland.ac.nz:
>
>
>  >
>  > On 19/03/2008, at 4:39 PM, Erin Hodgess wrote:
>  >
>  >> Dear R People:
>  >>
>  >> I want to get the class of all of the objects in my directory.
>  >>
>
>  >
>
> > Too easy!!!
>  >
>  > sapply(ls(),function(x){class(get(x))})
>  >
>
>
>  Thank you, Rolf. That supplied the needed index to the question I
>  struggled with yesterday: How to get a list of only my dataframes:
>
>  ls()[sapply(ls(),function(x){class(get(x))}) == "data.frame"]
>
>  --
>  David Winsemius
>
>
>
>  ______________________________________________
>  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.
>