Hello, everyone! I have list L that contains 99 data frames. All data frames have only one row, but a different number of columns. Some data frames have 3 columns, some - 6 columns, and some - 9 columns. The names of the first 3 columns are identical in all 99 data frames (e.g., A, B, and C). The names of columns 4:6 are identical in data frames that contain 6 and 9 columns (e.g., D, E, and F). So that L looks like this: L[[1]] A B C 2 3 4 L[[2]] A B C D E F 2 1 3 2 4 5 L[[3]] A B C D E F G H I 1 2 4 3 2 4 5 4 2 L[[4]] ... How can I merge all of those data frames into one large data frame - with 99 rows - such that all data are in the columns with correct names. Of course, I'd like the rows of the new large data frame that contain the data for less than 9 columns to have NAs in columns 4:9 (or 7:9). In other words, I want the first 3 rows of the new large data frame to look like this: A B C D E F G H I 2 3 4 NA NA NA NA NA NA 2 1 3 2 4 5 NA NA NA 1 2 4 3 2 4 5 4 2 Ideally, I'd like this merge to work for ANY number of individual small data frames in L - even if their total number within L is unknown. I tried merge - but it seems to me that it only works for 2 data frames, not for many. Thank you very much! -- Dimitri Liakhovitski MarketTools, Inc.
Hi Dimitri,
Not exceptionally elegant, but this should do it:
alldata <- as.data.frame(matrix(as.numeric(NA),nrow=99,ncol=9))
colnames(alldata) <- colnames(L[[?]])
( where ? is a 9-column data frame with the correct names )
foreach (i in 1:99) {
alldata[i,colnames(L[[i]])] <- L[[i]]
}
--Adam
On Fri, 19 Dec 2008, Dimitri Liakhovitski wrote:
> Hello, everyone!
>
> I have list L that contains 99 data frames. All data frames have only
> one row, but a different number of columns. Some data frames have 3
> columns, some - 6 columns, and some - 9 columns. The names of the
> first 3 columns are identical in all 99 data frames (e.g., A, B, and
> C). The names of columns 4:6 are identical in data frames that contain
> 6 and 9 columns (e.g., D, E, and F). So that L looks like this:
>
> L[[1]]
> A B C
> 2 3 4
> L[[2]]
> A B C D E F
> 2 1 3 2 4 5
> L[[3]]
> A B C D E F G H I
> 1 2 4 3 2 4 5 4 2
> L[[4]]
> ...
>
>
> How can I merge all of those data frames into one large data frame -
> with 99 rows - such that all data are in the columns with correct
> names. Of course, I'd like the rows of the new large data frame that
> contain the data for less than 9 columns to have NAs in columns 4:9
> (or 7:9).
> In other words, I want the first 3 rows of the new large data frame to
> look like this:
> A B C D E F G H I
> 2 3 4 NA NA NA NA NA NA
> 2 1 3 2 4 5 NA NA NA
> 1 2 4 3 2 4 5 4 2
>
> Ideally, I'd like this merge to work for ANY number of individual
> small data frames in L - even if their total number within L is
> unknown.
>
> I tried merge - but it seems to me that it only works for 2 data
> frames, not for many.
> Thank you very much!
> --
> Dimitri Liakhovitski
> MarketTools, Inc.
>
> ______________________________________________
> 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.
>
Try this:> L <- list(data.frame(A=2, B=3, C=4),+ data.frame(A=2, B=1, C=3, D=2, E=4, F=5), + data.frame(A=1, B=2, C=4, D=3, E=2, F=4, G=5, H=4, I=2))> library(plyr) > do.call(rbind.fill, L)A B C D E F G H I 1 2 3 4 NA NA NA NA NA NA 2 2 1 3 2 4 5 NA NA NA 3 1 2 4 3 2 4 5 4 2 On Fri, Dec 19, 2008 at 5:48 PM, Dimitri Liakhovitski <ld7631 at gmail.com> wrote:> Hello, everyone! > > I have list L that contains 99 data frames. All data frames have only > one row, but a different number of columns. Some data frames have 3 > columns, some - 6 columns, and some - 9 columns. The names of the > first 3 columns are identical in all 99 data frames (e.g., A, B, and > C). The names of columns 4:6 are identical in data frames that contain > 6 and 9 columns (e.g., D, E, and F). So that L looks like this: > > L[[1]] > A B C > 2 3 4 > L[[2]] > A B C D E F > 2 1 3 2 4 5 > L[[3]] > A B C D E F G H I > 1 2 4 3 2 4 5 4 2 > L[[4]] > ... > > > How can I merge all of those data frames into one large data frame - > with 99 rows - such that all data are in the columns with correct > names. Of course, I'd like the rows of the new large data frame that > contain the data for less than 9 columns to have NAs in columns 4:9 > (or 7:9). > In other words, I want the first 3 rows of the new large data frame to > look like this: > A B C D E F G H I > 2 3 4 NA NA NA NA NA NA > 2 1 3 2 4 5 NA NA NA > 1 2 4 3 2 4 5 4 2 > > Ideally, I'd like this merge to work for ANY number of individual > small data frames in L - even if their total number within L is > unknown. > > I tried merge - but it seems to me that it only works for 2 data > frames, not for many. > Thank you very much! > -- > Dimitri Liakhovitski > MarketTools, Inc. > > ______________________________________________ > 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. >