[R] split & rbind (cast) dataframe

[Ista Zahn]

Hi Johannes,

Your example is tricky because the original df1 does not contain id
columns that identify each cell in df2. If you want to use the
reshape2 package for this I think you have to add a second id
variable:

df1 <- data.frame(col1 = c("A","A","B","B"),col2 = c(1:4), col3 = c(1:4))

library(reshape2)
library(plyr)

df1 <- ddply(df1,
             "col1",
             transform,
             col0 = 1:length(col1))

tmp <- melt(df1, id.vars = c("col0","col1"))
dcast(tmp, col0 ~ col1 + variable)

Best,
Ista

On Fri, Jan 11, 2013 at 7:46 AM, Johannes Radinger
<johannesradinger at gmail.com> wrote:
> Hi,
>
> I would like to split dataframe based on one colum and want
> to connect the two dataframes by rows (like rbind). Here a small example:
>
> # The orgininal dataframe
> df1 <- data.frame(col1 = c("A","A","B","B"),col2 = c(1:4), col3 = c(1:4))
>
> # The datafame how it could look like
> df2 <- data.frame(A.col2 = c(1,2), A.col3 = c(1,2), B.col2 = c(3,4),
> B.col3 = c(3,4))
>
> I think I already did a similar procedure sometime ago with the
> cast() command from reshape-package but I cant remember correctly...
> ...maybe someone can point me to the correct formula...
>
> Best
>
> /johannes
>
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