[R] dataframe rbind

[David L Carlson]

This will work, although depending on what you are trying to do, there may be a better way:

> DF <- data.frame(a=rnorm(10),b=runif(10),ID=0)
> for (i in 1:10){
+ DF <- rbind(DF, data.frame(a=rnorm(10),b=runif(10),ID=i))}
> str(DF)
'data.frame':   110 obs. of  3 variables:
 $ a : num  0.792 0.141 -1.091 -0.918 1.265 ...
 $ b : num  0.5935 0.695 0.075 0.0827 0.852 ...
 $ ID: num  0 0 0 0 0 0 0 0 0 0 ...

For example:

> DF <- data.frame(a=rnorm(110), b=rnorm(110), ID=rep(0:10, each=10))
> str(DF)
'data.frame':   110 obs. of  3 variables:
 $ a : num  -1.91926 0.00791 0.65523 0.95019 1.23822 ...
 $ b : num  0.344 1.281 2.057 -1.69 -0.268 ...
 $ ID: int  0 0 0 0 0 0 0 0 0 0 ...

-------------------------------------
David L Carlson
Department of Anthropology
Texas A&M University
College Station, TX 77840-4352


-----Original Message-----
From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Troels Ring
Sent: Friday, December 4, 2015 10:03 AM
To: r-help at r-project.org
Subject: [R] dataframe rbind

Dear friends - I have a very simple question -
I generate a number of dataframes with identical names and want to 
combine them into one large dataframe with the same names -
here is an example

DF <- data.frame(a=rnorm(10),b=runif(10),ID=0)
for (i in 1:10){
DF <- DF+rbind(data.frame(a=rnorm(10),b=runif(10),ID=i))}

- the dataframe do not grow as I thought it would.

How would I do this?

All best wishes
Troels Ring
Nephrology
Aalborg
Denmark

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