I have two lists:
xa <- list( X=c(1,2,3), Y=c(4,5,6), Z=c(7,8,9) )
xb <- with( barley, tapply( X=seq(1:nrow(barley)), INDEX=site
, FUN=function(z)yield[z]))
I can convert xa to a dataframe easily with:
as.data.frame(xa)
But if i try the same with xb I get:
as.data.frame(xb)
Error in as.data.frame.default(xb) :
can't coerce array into a data.frame
What helps?
(NB: I know the formula for xb is stupid, but it generates the same
type of list as the list I get from my real problem.)
Wolfram
Wolfram, try unlist(xb) Andrew On Wednesday 10 March 2004 06:58, Wolfram Fischer wrote:> I have two lists: > > xa <- list( X=c(1,2,3), Y=c(4,5,6), Z=c(7,8,9) ) > > xb <- with( barley, tapply( X=seq(1:nrow(barley)), INDEX=site > , FUN=function(z)yield[z])) > > I can convert xa to a dataframe easily with: > as.data.frame(xa) > > But if i try the same with xb I get: > as.data.frame(xb) > Error in as.data.frame.default(xb) : > can't coerce array into a data.frame > > What helps? > > (NB: I know the formula for xb is stupid, but it generates the same > type of list as the list I get from my real problem.) > > Wolfram > > ______________________________________________ > 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-- Andrew Robinson Ph: 208 885 7115 Department of Forest Resources Fa: 208 885 6226 University of Idaho E : andrewr at uidaho.edu PO Box 441133 W : http://www.uidaho.edu/~andrewr Moscow ID 83843 Or: http://www.biometrics.uidaho.edu No statement above necessarily represents my employer's opinion.
That gives you a vector, not a data frame. The problem is that the object returned by tapply is a 1-d array of list. When as.data.frame() is called, the default method doesn't know how to handle arrays and gives the error. What you really want for this particular case is to treat the object as a list, so the unorthodox way is: as.data.frame.list(xb) OK, I didn't really say that... Andy> From: Andrew Robinson > > Wolfram, > > try > > unlist(xb) > > Andrew > > On Wednesday 10 March 2004 06:58, Wolfram Fischer wrote: > > I have two lists: > > > > xa <- list( X=c(1,2,3), Y=c(4,5,6), Z=c(7,8,9) ) > > > > xb <- with( barley, tapply( X=seq(1:nrow(barley)), INDEX=site > > , FUN=function(z)yield[z])) > > > > I can convert xa to a dataframe easily with: > > as.data.frame(xa) > > > > But if i try the same with xb I get: > > as.data.frame(xb) > > Error in as.data.frame.default(xb) : > > can't coerce array into a data.frame > > > > What helps? > > > > (NB: I know the formula for xb is stupid, but it generates the same > > type of list as the list I get from my real problem.) > > > > Wolfram > > > > ______________________________________________ > > 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 > > -- > Andrew Robinson Ph: 208 885 7115 > Department of Forest Resources Fa: 208 885 6226 > University of Idaho E : andrewr at uidaho.edu > PO Box 441133 W : > http://www.uidaho.edu/~andrewr > Moscow ID 83843 > Or: http://www.biometrics.uidaho.edu > No statement above necessarily represents my employer's opinion. > > ______________________________________________ > 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}}
On 10 Mar 2004 at 15:58, Wolfram Fischer wrote: It's a bit strange. The following should work: as.data.frame(as.matrix(xb)) Kjetil Halvorsen> I have two lists: > > xa <- list( X=c(1,2,3), Y=c(4,5,6), Z=c(7,8,9) ) > > xb <- with( barley, tapply( X=seq(1:nrow(barley)), INDEX=site > , FUN=function(z)yield[z])) > > I can convert xa to a dataframe easily with: > as.data.frame(xa) > > But if i try the same with xb I get: > as.data.frame(xb) > Error in as.data.frame.default(xb) : > can't coerce array into a data.frame > > What helps? > > (NB: I know the formula for xb is stupid, but it generates the same > type of list as the list I get from my real problem.) > > Wolfram > > ______________________________________________ > 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