On Wed, 2 May 2018, Kevin E. Thorpe wrote:
I suspect this is pretty easy, but I'm having trouble figuring it out.
Basically, I have a list of data frames such as the following example:
list(A=data.frame(x=1:2, y=3:4),B=data.frame(x=5:6,y=7:8))
I would like to turn this into data frame where the list elements are
essentially rbind'ed together and the element name becomes a new variable.
For example, I would like to turn the list above into a data frame that looks
like this:
data.frame(type=c("A","A","B","B"),x=c(1:2,5:6),y=c(3:4,7:8))
Appreciate any pointers.
Kevin
Hi, Kevin.
Here's code that will generate your desired data frame.
# List as provided
thelist <- list(A=data.frame(x=1:2, y=3:4),B=data.frame(x=5:6,y=7:8))
thelist
# Creating the type-vector
type <- c()
for(i in 1:length(thelist)){
type <- c(type, rep(names(thelist)[i], sapply(thelist, nrow)[i]))
}
# Creating the data frame
df <- data.frame(type, do.call(rbind.data.frame, c(thelist, make.row.names
= FALSE)))
df
Kind regards,
Eivind K. Dovik
Bergen, NO
--
Kevin E. Thorpe
Head of Biostatistics, Applied Health Research Centre (AHRC)
Li Ka Shing Knowledge Institute of St. Michael's Hospital
Assistant Professor, Dalla Lana School of Public Health
University of Toronto
email: kevin.tho...@utoronto.ca Tel: 416.864.5776 Fax: 416.864.3016
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
