[R] Convert rbind of lists to data.frame

arun smartpink111 at yahoo.com
Thu Aug 1 00:26:58 CEST 2013


May be this helps:

l1<- list('a',1)
 l2<- list('b',2)
 l3<- list('c',3)
df1<-data.frame(mapply(`c`,l1,l2,l3,SIMPLIFY=FALSE),stringsAsFactors=FALSE)
 colnames(df1)<-paste0("X",1:2)
  str(df1)
#'data.frame':    3 obs. of  2 variables:
# $ X1: chr  "a" "b" "c"
# $ X2: num  1 2 3

A.K.



----- Original Message -----
From: Shaun Jackman <sjackman at gmail.com>
To: R help <r-help at r-project.org>
Cc: 
Sent: Wednesday, July 31, 2013 5:58 PM
Subject: [R] Convert rbind of lists to data.frame

I'm trying to build a data.frame row-by-row like so:

df <- data.frame(rbind(list('a',1), list('b', 2), list('c', 3)))

I was surprised to see that the columns of the resulting data.frame
are stored in lists rather than vectors.

str(df)
'data.frame': 3 obs. of  2 variables:
$ X1:List of 3
  ..$ : chr "a"
  ..$ : chr "b"
  ..$ : chr "c"
$ X2:List of 3
  ..$ : num 1
  ..$ : num 2
  ..$ : num 3

The desired result is:

str(df)
'data.frame': 3 obs. of  2 variables:
$ X1: chr  "a" "b" "c"
$ X2: num  1 2 3

The following works, but is rather ugly:

df <- data.frame(lapply(data.frame(rbind(list('a',1), list('b', 2),
list('c', 3))), unlist))

Thanks,
Shaun

______________________________________________
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.




More information about the R-help mailing list