As part of my work, I am trying to append matrices onto data frames.
Naively I assumed that when rbinding a data.frame and matrix, the matrix
would be coerced and appended, keeping the names from the data frame.
Clearly, I am not fully understanding the process by which rbind works.
Example code:
> A<-data.frame(1,1,1); names(A)=letters[1:3] ; B<-matrix(0,2,3)
> rbind(A,B)
Error in match.names(clabs, names(xi)) : names do not match previous names:
V1, V2, V3
> rbind(A,as.data.frame(B))
Error in match.names(clabs, names(xi)) : names do not match previous names:
V1, V2, V3
Is there a "right" way to combine the two such that the both end up
having the same column names?
I have tried to understand the deparse.level argument of rbind, but it
doesn't seem to do what I'm asking.
Thank you for any help you can give.
Gregg
--
Gregg Lind, M.S.
Division of Epidemiology and Community Health
School of Public Health
University of Minnesota, United States
This takes care of things quite nicely. The other solutions (explicitly coercing things) work as well, but this seems to me the minimum necessary solution for my particular problem. (P.s.: I hope I responded in the correct way to ensure threading... to the main list address.) A<- data.frame(1,1,1); names(A)=letters[1:3] ; B<-matrix(0,2,3) colnames(B) <- colnames(A) rbind(A,B) GL jim holtman wrote:> colnames(B) <- colnames(A) > > On 3/5/07, *Gregg Lind* <lind1199@umn.edu <mailto:lind1199@umn.edu>> > wrote: > > > As part of my work, I am trying to append matrices onto data frames. > Naively I assumed that when rbinding a data.frame and matrix, the > matrix > would be coerced and appended, keeping the names from the data frame. > Clearly, I am not fully understanding the process by which rbind > works. > > Example code: > > > A<- data.frame(1,1,1); names(A)=letters[1:3] ; B<-matrix(0,2,3) > > rbind(A,B) > Error in match.names(clabs, names(xi)) : names do not match > previous names: > V1, V2, V3 > > rbind(A,as.data.frame(B)) > Error in match.names(clabs, names(xi)) : names do not match > previous names: > V1, V2, V3 > > > > Is there a "right" way to combine the two such that the both end up > having the same column names? > > I have tried to understand the deparse.level argument of rbind, but it > doesn't seem to do what I'm asking. > > Thank you for any help you can give. > > > Gregg > -- > Gregg Lind, M.S. > > Division of Epidemiology and Community Health > School of Public Health > University of Minnesota, United States > > ______________________________________________ > R-help@stat.math.ethz.ch <mailto:R-help@stat.math.ethz.ch> 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. > > > > > -- > Jim Holtman > Cincinnati, OH > +1 513 646 9390 > > What is the problem you are trying to solve?[[alternative HTML version deleted]]
Cody_Hamilton at Edwards.com
2007-Mar-05 22:40 UTC
[R] Rbind with data frames -- column names question
Gregg,
What about
A<-data.frame(1,1,1); names(A)=letters[1:3] ; B<-matrix(0,2,3)
B<-as.data.frame(B)
names(B)<-names(A)
rbind(A,B)
-Cody
Gregg Lind
<lind1199 at umn.edu
> To
Sent by: r-help at stat.math.ethz.ch
r-help-bounces at st cc
at.math.ethz.ch
Subject
[R] Rbind with data frames --
03/05/2007 02:06 column names question
PM
As part of my work, I am trying to append matrices onto data frames.
Naively I assumed that when rbinding a data.frame and matrix, the matrix
would be coerced and appended, keeping the names from the data frame.
Clearly, I am not fully understanding the process by which rbind works.
Example code:
> A<-data.frame(1,1,1); names(A)=letters[1:3] ; B<-matrix(0,2,3)
> rbind(A,B)
Error in match.names(clabs, names(xi)) : names do not match previous names:
V1, V2, V3
> rbind(A,as.data.frame(B))
Error in match.names(clabs, names(xi)) : names do not match previous names:
V1, V2, V3
Is there a "right" way to combine the two such that the both end up
having the same column names?
I have tried to understand the deparse.level argument of rbind, but it
doesn't seem to do what I'm asking.
Thank you for any help you can give.
Gregg
--
Gregg Lind, M.S.
Division of Epidemiology and Community Health
School of Public Health
University of Minnesota, United States
______________________________________________
R-help at stat.math.ethz.ch 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.
I don't know if this is the "right" way, but I think this would work (I'm assuming you want the result to be a data frame): data.frame(rbind(as.matrix(A),B)) You might get a warning about row names, but I think it works OK. On 05/03/07, Gregg Lind <lind1199 at umn.edu> wrote:> > As part of my work, I am trying to append matrices onto data frames. > Naively I assumed that when rbinding a data.frame and matrix, the matrix > would be coerced and appended, keeping the names from the data frame. > Clearly, I am not fully understanding the process by which rbind works. > > Example code: > > > A<-data.frame(1,1,1); names(A)=letters[1:3] ; B<-matrix(0,2,3) > > rbind(A,B) > Error in match.names(clabs, names(xi)) : names do not match previous names: > V1, V2, V3 > > rbind(A,as.data.frame(B)) > Error in match.names(clabs, names(xi)) : names do not match previous names: > V1, V2, V3 > > > > Is there a "right" way to combine the two such that the both end up > having the same column names? > > I have tried to understand the deparse.level argument of rbind, but it > doesn't seem to do what I'm asking. > > Thank you for any help you can give. > > > Gregg > -- > Gregg Lind, M.S. > > Division of Epidemiology and Community Health > School of Public Health > University of Minnesota, United States > > ______________________________________________ > R-help at stat.math.ethz.ch 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. >-- ================================David Barron Said Business School University of Oxford Park End Street Oxford OX1 1HP