[R] A way to list only variables or functions?

[Shin, Daehyok]

Thanks, Petr.
The ls.objects function displays a really nice summary about objects.
Surely, I will use it more often than ls or ls.str.

Daehyok Shin

> -----Original Message-----
> From: Petr Pikal [mailto:petr.pikal at precheza.cz]
> Sent: Monday, June 21, 2004 AM 11:01
> To: Duncan Murdoch; r-help at stat.math.ethz.ch; sdhyok at email.unc.edu
> Subject: Re: [R] A way to list only variables or functions?
> 
> 
> 
> 
> On 21 Jun 2004 at 10:39, Duncan Murdoch wrote:
> 
> > On Mon, 21 Jun 2004 09:53:35 -0400, "Shin, Daehyok"
> > <sdhyok at email.unc.edu> wrote :
> > 
> > >Glad to know useful functions.
> > >How about adding lsv.str function to list only variables bound to
> > >values? In my opinion, we are more interested in values than
> > >functions in the process of data analysis.
> > 
> > In R, functions often contain useful information about data (in their
> > attached environments).  For example, the result of a smoothing fit
> > could include a function that calculates the fitted value at any
> > point.  So the distinction between functions and values isn't as clear
> > as you seem to be thinking.
> > 
> > However, it would be useful to get a slightly more informative version
> > of ls(), that returned a data.frame containing the name, length,
> > class, and other useful information for each object. Then if you
> > didn't want to see functions, you'd just select based on the class (or
> > mode, or some other column).
> > 
> > I seem to recall that S-PLUS has such a function, but I forget the
> > name of it.   Probably R does too, on CRAN if not in the base
> > packages.
> 
> Some time ago there was a thread about such matter too and from 
> that time i use a function
> 
> > ls.objects
> function (pos = 1, pattern, order.by) 
> {
>     napply <- function(names, fn) sapply(names, function(x) 
> fn(get(x, 
>         pos = pos)))
>     names <- ls(pos = pos, pattern = pattern)
>     obj.class <- napply(names, function(x) as.character(class(x))[1])
>     obj.mode <- napply(names, mode)
>     obj.type <- ifelse(is.na(obj.class), obj.mode, obj.class)
>     obj.size <- napply(names, object.size)
>     obj.dim <- t(napply(names, function(x) 
> as.numeric(dim(x))[1:2]))
>     vec <- is.na(obj.dim)[, 1] & (obj.type != "function")
>     obj.dim[vec, 1] <- napply(names, length)[vec]
>     out <- data.frame(obj.type, obj.size, obj.dim)
>     names(out) <- c("Type", "Size", "Rows", "Columns")
>     if (!missing(order.by)) 
>         out <- out[order(out[[order.by]]), ]
>     out
> }
> 
> which gives some more information about objects than plain ls()
> 
> Cheers
> Petr
> 
> > 
> > Duncan Murdoch
> > 
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> 
> Petr Pikal
> petr.pikal at precheza.cz
> 
> 
>