R help - Sep 2010 - Splitting a data frame into several completely separate data frames

Hello again,

How do I split a data frame into smaller, completely separate data frames 
(rather than separate data frames comprising a single "list")?
Consider the
following data, and my coding attempt:

x <- read.table(textConnection("id type number
indv.1 bagel 6
indv.2 bagel 1
indv.3 donuts 10
indv.4 donuts 9"), header = TRUE)
closeAllConnections()

x.split <- split(x, x$type)

This is where I'm stuck. Now I have one "list" comprised of
different data
frames, but what I want is separate data frames.

Ideally, I'd like to design a loop to give sequentially-numbered names to
the
separate data frames I create. This is because my real data will have many more 
than two groups (i.e., many more types of things than just "bagels"
versus
"donuts") and the number of groups will vary when I apply the same
code to
different data sets.

Many thanks in advance for your replies!
-----------------------------------
Josh Banta, Ph.D
Center for Genomics and Systems Biology
New York University
100 Washington Square East
New York, NY 10003
Tel: (212) 998-8465
http://plantevolutionaryecology.org



      
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On 26.09.2010 14:52, Josh B wrote:
> Hello again,
>
> How do I split a data frame into smaller, completely separate data frames
> (rather than separate data frames comprising a single "list")?
Consider the
> following data, and my coding attempt:
>
> x<- read.table(textConnection("id type number
> indv.1 bagel 6
> indv.2 bagel 1
> indv.3 donuts 10
> indv.4 donuts 9"), header = TRUE)
> closeAllConnections()
>
> x.split<- split(x, x$type)

Although I doubt it is more convenient to have so many data.frames 
around (rather than having them nicely grouped in a list), you can 
simply do that in a loop:

for(i in names(x.split))
     assign(paste("nameOfDataFrame", i, sep="_"), temp[[i]])

Uwe Ligges

> This is where I'm stuck. Now I have one "list" comprised of
different data
> frames, but what I want is separate data frames.
>
> Ideally, I'd like to design a loop to give sequentially-numbered names
to the
> separate data frames I create. This is because my real data will have many
more
> than two groups (i.e., many more types of things than just
"bagels" versus
> "donuts") and the number of groups will vary when I apply the
same code to
> different data sets.
>
> Many thanks in advance for your replies!
> -----------------------------------
> Josh Banta, Ph.D
> Center for Genomics and Systems Biology
> New York University
> 100 Washington Square East
> New York, NY 10003
> Tel: (212) 998-8465
> http://plantevolutionaryecology.org
>
>
>
>
> 	[[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.

On Sun, Sep 26, 2010 at 8:52 AM, Josh B <joshb41 at yahoo.com>
wrote:
> Hello again,
>
> How do I split a data frame into smaller, completely separate data frames
> (rather than separate data frames comprising a single "list")?
Consider the
> following data, and my coding attempt:
>
> x <- read.table(textConnection("id type number
> indv.1 bagel 6
> indv.2 bagel 1
> indv.3 donuts 10
> indv.4 donuts 9"), header = TRUE)
> closeAllConnections()
>
> x.split <- split(x, x$type)
>
> This is where I'm stuck. Now I have one "list" comprised of
different data
> frames, but what I want is separate data frames.
>
> Ideally, I'd like to design a loop to give sequentially-numbered names
to the
> separate data frames I create. This is because my real data will have many
more
> than two groups (i.e., many more types of things than just
"bagels" versus
> "donuts") and the number of groups will vary when I apply the
same code to
> different data sets.
>
Its normally better to keep them in a list but if you must:
> attach(x.split)
> bagel
      id  type number
1 indv.1 bagel      6
2 indv.2 bagel      1

Note that the attach puts the individual data frames in position 2 of
your search list and not in your workspace so its mainly useful if you
don't need to modify them. e.g. try this to see your search list:

search()

and this to list them:
> ls(2)
[1] "bagel"  "donuts"
>
> ls(as.environment("x.split"))
[1] "bagel"  "donuts"

If you want to be able to modify them or to have them directly in your
global workspace then use Uwe's answer.

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