[R] Adding data.frames together

Liaw, Andy andy_liaw at merck.com
Wed Mar 10 00:27:27 CET 2004


Use rbind() (for row-bind).  Here are some examples:

> d1 <- data.frame(x=1, y=1)
> d2 <- data.frame(x=1:2, y=1:2)
> d3 <- data.frame(x=3, y=3)
> rbind(d1,d2,d3)
   x y
1  1 1
11 1 1
2  2 2
12 3 3
> do.call("rbind", list(d1,d2,d3))
   x y
1  1 1
11 1 1
2  2 2
12 3 3

[or even this:]

> do.call("rbind", eval(parse(text=paste(paste("list(",
paste("d",1:3,sep="",collapse=","), ")")))))
   x y
1  1 1
11 1 1
2  2 2
12 3 3

HTH,
Andy

> From: John Sweval
> 
> I have a series of data frames that are identical structurally, i.e. -
> made with the same code, but I need to add them together so that they
> become one, longer, data frame, i.e. - each of the slot vectors are
> increased in length by the length of the added data frame vectors.
> 
> So if I have df1 with a slot A so that length(df1$A) = 100 and I have
> df2 with a slot A so that length(df2$A)=200 then I need a method to
> create df3 its slot A is the df1$A plus df2$A such that 
> length(df3$A) =
> 300.
> 
> It does not appear that if you use data.frame to join two 
> data frames it
> just adds the slots of both sources to the destination data frame and
> that is not what I want.
> 
> In my finally solution, I need to do this with multiple 
> data.frames that
> slot-wise are identical, but each slot length is different 
> between data
> frames.
> 
> Seems like there should be an easy solution, but I just have not
> stumbled across it in the documentation.
> 
> Thanks,
> John C. Sweval
>   Database Architect
>   Illumigen Biosciences, Inc.
>     Email: jsweval at illumigen.com
>     Phone: 206-378-0400
>     Fax: 206-378-0408
> 
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html
> 
> 


------------------------------------------------------------------------------
Notice:  This e-mail message, together with any attachments,...{{dropped}}




More information about the R-help mailing list