R help - Nov 2011 - List of lists to data frame?

I would like to make the following faster:

	df <- NULL
	for(i in 1:length(s))
	{
		df <- rbind(df, cbind(names(s[i]), time(s[[i]]$series), 
as.vector(s[[i]]$series), s[[i]]$category))
	}
	names(df) <- c("name", "time", "value",
"category")
	return(df)

The s object is a list of lists. It is constructed like:

s[["object"]] <- list(. . . . . .)

where "object" would be the name associated with this list
s[[i]]$series
is a 'ts' object and s[[i]]$category is a name.

Constructing this list is reasonably fast but to do some more processing 
on the data it would be easier if it were converted to a data frame. 
Right now the above code is unacceptably slow at converting this list of 
lists to a data frame. Any suggestions on how to optimize this are 
welcome.

Thank you.

Kevin

	[[alternative HTML version deleted]]

unlist(..., recursive = F)

Michael

On Wed, Nov 16, 2011 at 6:20 PM,  <rkevinburton at charter.net>
wrote:
>
> I would like to make the following faster:
>
> ? ? ? ?df <- NULL
> ? ? ? ?for(i in 1:length(s))
> ? ? ? ?{
> ? ? ? ? ? ? ? ?df <- rbind(df, cbind(names(s[i]), time(s[[i]]$series),
> as.vector(s[[i]]$series), s[[i]]$category))
> ? ? ? ?}
> ? ? ? ?names(df) <- c("name", "time",
"value", "category")
> ? ? ? ?return(df)
>
> The s object is a list of lists. It is constructed like:
>
> s[["object"]] <- list(. . . . . .)
>
> where "object" would be the name associated with this list
s[[i]]$series
> is a 'ts' object and s[[i]]$category is a name.
>
> Constructing this list is reasonably fast but to do some more processing
> on the data it would be easier if it were converted to a data frame.
> Right now the above code is unacceptably slow at converting this list of
> lists to a data frame. Any suggestions on how to optimize this are
> welcome.
>
> Thank you.
>
> Kevin
>
> ? ? ? ?[[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
>