kamokoi
2008-Jan-30 02:02 UTC
[R] assign column classes when creating a data frame from several vectors
R-helpers,
Thanks in advance for your help. I am an R newbie and I am having trouble
figuring out the easiest/most efficient way to assign classes to columns in
a newly created data frame. R seems to want to convert everything to a
factor when I use the cbind function to compile vectors into a data frame.
ID<-seq(1,10,1)
TREAT<-c(rep("B",5),rep("G",5))
T1<-rnorm(10,50,10)
T2<-rnorm(10,15,10)
data<-as.data.frame(cbind(ID,TREAT,T1,T2))
data
ID TREAT T1 T2
1 1 B 41.506987139726 20.0964019326073
2 2 B 53.7814271299636 4.9049787919397
3 3 B 54.118333111305 18.2182330777312
4 4 B 48.8591282265369 12.4561774992591
5 5 B 32.3160291908524 23.6665858869752
6 6 G 52.3181626145907 -4.60173207209386
7 7 G 53.4170845444393 2.30744010208809
8 8 G 60.4200675102018 10.9954680147326
9 9 G 42.6264529901835 9.22980548637643
10 10 G 40.2748346897501 14.2458580129253
sapply(data,class)
ID TREAT T1 T2
"factor" "factor" "factor" "factor"
The only way I can find to get around this is to use stringsAsFactors=FALSE
and then assign classes to each of the columns individually.
data<-as.data.frame(cbind(ID,TREAT,T1,T2), stringsAsFactors=F)
data$ID<-as.factor(data$ID)
data$TREAT<-as.factor(data$TREAT)
data$T1<-as.numeric(data$T1)
data$T2<-as.numeric(data$T2)
sapply(data,class)
ID TREAT T1 T2
"factor" "factor" "numeric" "numeric"
Is there a more efficient way to do the same thing.
Thanks for your help.
--
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jim holtman
2008-Jan-30 02:24 UTC
[R] assign column classes when creating a data frame from several vectors
By doing "cbind(ID,TREAT,T1,T2)" you are coercing everything to character and therefore factors in the dataframe. Why didn't you just say: data<-data.frame(ID,TREAT,T1,T2) On Jan 29, 2008 9:02 PM, kamokoi <kamokoi at gmail.com> wrote:> > R-helpers, > > Thanks in advance for your help. I am an R newbie and I am having trouble > figuring out the easiest/most efficient way to assign classes to columns in > a newly created data frame. R seems to want to convert everything to a > factor when I use the cbind function to compile vectors into a data frame. > > ID<-seq(1,10,1) > TREAT<-c(rep("B",5),rep("G",5)) > T1<-rnorm(10,50,10) > T2<-rnorm(10,15,10) > data<-as.data.frame(cbind(ID,TREAT,T1,T2)) > > data > > ID TREAT T1 T2 > 1 1 B 41.506987139726 20.0964019326073 > 2 2 B 53.7814271299636 4.9049787919397 > 3 3 B 54.118333111305 18.2182330777312 > 4 4 B 48.8591282265369 12.4561774992591 > 5 5 B 32.3160291908524 23.6665858869752 > 6 6 G 52.3181626145907 -4.60173207209386 > 7 7 G 53.4170845444393 2.30744010208809 > 8 8 G 60.4200675102018 10.9954680147326 > 9 9 G 42.6264529901835 9.22980548637643 > 10 10 G 40.2748346897501 14.2458580129253 > > sapply(data,class) > ID TREAT T1 T2 > "factor" "factor" "factor" "factor" > > The only way I can find to get around this is to use stringsAsFactors=FALSE > and then assign classes to each of the columns individually. > > data<-as.data.frame(cbind(ID,TREAT,T1,T2), stringsAsFactors=F) > data$ID<-as.factor(data$ID) > data$TREAT<-as.factor(data$TREAT) > data$T1<-as.numeric(data$T1) > data$T2<-as.numeric(data$T2) > sapply(data,class) > ID TREAT T1 T2 > "factor" "factor" "numeric" "numeric" > > Is there a more efficient way to do the same thing. > > Thanks for your help. > > > > -- > View this message in context: http://www.nabble.com/assign-column-classes-when-creating-a-data-frame-from-several-vectors-tp15174042p15174042.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. >-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve?