Converting a list to a data frame

Good morning.

Novice usR. Here.

I am following this string, among many, learning as I go.

Quick question please?

I thought that perhaps ata.frame was part of the zoo pkg, b/c when I
searched it came up in help?

However, evidently not or I am not using it properly.

Please advise, thank you.

x <- list(A=data.frame(x=1:2, y=3:4),B=data.frame(x=5:6,y=7:8))

x2 <- do.call<http://do.call>(rbind, lapply(names(x), function(z)

ata.frame(type=z, dat[[z]])))

#Error in ata.frame(type = z, dat[[z]]) : could not find function
"ata.frame"

?ata.frame

??ata.frame #Looks like it's part of the zoo package?

install.packages("zoo")

#Typo: dat[[z]] should be x[[z]]:

x <- list(A=data.frame(x=1:2, y=3:4),B=data.frame(x=5:6,y=7:8))

x2 <- do.call<http://do.call>(rbind, lapply(names(x), function(z)

ata.frame(type=z, x[[z]])))

#Error in ata.frame(type = z, dat[[z]]) : still cannot find function
"ata.frame"?

*William H. Poling, Ph.D.*

*From:* R-help [mailto:r-help-bounces at r-project.org] *On Behalf Of
*Huzefa Khalil
*Sent:* Wednesday, May 02, 2018 1:24 PM
*To:* Kevin E. Thorpe <kevin.thorpe at utoronto.ca<mailto:kevin.thorpe at utoronto.ca>>
*Cc:* R Help Mailing List <r-help at r-project.org<mailto:r-help at r-project.org>>
*Subject:* Re: [R] Converting a list to a data frame

Hi Kevin,

There is probably a better way, but it can be done in two steps like this

temp <- list(A=data.frame(x=1:2, y=3:4),B=data.frame(x=5:6,y=7:8))

temp <- lapply(names(temp), function(n, temp) {
temp[[n]]$type <- n
return(temp[[n]])
}, temp = temp)

do.call<http://do.call>(rbind, temp)



On Wed, May 2, 2018 at 1:11 PM, Kevin E. Thorpe
<kevin.thorpe at utoronto.ca <mailto:kevin.thorpe at utoronto.ca<mailto:kevin.thorpe at utoronto.ca%20%3cmailto:kevin.thorpe at utoronto.ca>>>
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

--
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.thorpe at utoronto.ca<mailto:kevin.thorpe at utoronto.ca> <mailto:kevin.thorpe at utoronto.ca>

Tel: 416.864.5776 Fax: 416.864.3016