Re: [Rd] how do I join two lists of the same type ?

From: Stavros Macrakis <macrakis_at_alum.mit.edu>
Date: Thu, 31 Dec 2009 01:23:20 -0500

rbind will work for data frames, but the type of your myData is not clear. Is it a list of data frames, in which case you probably want rbind(myData[[1]], myData[[2]])? I don't understand why you write NewData[1] for your desired result and not NewData. Do you perhaps want list(rbind(myData[[1]], myData[[2]])) for some particular reason?

Example:

myData <- list ( data.frame(a=1:2, b=12:13, c=14:15),

                         data.frame(a=3:4, b=14:15, c=16:17))

> rbind(myData[[1]],myData[[2]])

  a b c
1 1 12 14
2 2 13 15
3 3 14 16
4 4 15 17
>

Note:
> myData[1] a slice of the myData list, itself a list (of length 1),
and equivalent to myData[1:1]
[[1]]
  a b c
1 1 12 14
2 2 13 15

> myData[[1]] an *element* of the myData list, a data frame
  a b c
1 1 12 14
2 2 13 15
>

On Thu, Dec 31, 2009 at 1:09 AM, Steve Mew <steve.mew_at_alphaedge.org> wrote:

> I want to join two lists but am so for not having any luck. Can anyone
> assist ?
>
>
> Variable: myData[1]
>
> "Data.Id" "Data.Length" "Data.Weight"
> "1" 12 12
> "2" 45 23
>
>
>
> Variable: myData[2]
>
> "Data.Id" "Data.Length" "Data.Weight"
> "3" 25 56
> "4" 55 288
>
>
> How do I join them together to get this ? ;
>
>
> Variable: NewData[1]
>
> "Data.Id" "Data.Length" "Data.Weight"
> "1" 12 12
> "2" 45 23
> "3" 25 56
> "4" 55 288
>
>
> I have tried rbind,cbind,append, merge no luck so far...
> Any help greatly appreciated...
>
> Thanks
>
> Steve
>
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>
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https://stat.ethz.ch/mailman/listinfo/r-devel Received on Thu 31 Dec 2009 - 06:26:56 GMT

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