Hi,
?merge(), ?rbind(), or ?join() from library(plyr)
set.seed(5)
trainset<-data.frame(ID=1:10,col2=runif(10,0,1))
?dataset <- trainset
?trainset<-dataset[-testindex,]
testset<-dataset[testindex,]
merge(testset,trainset,by=c("ID","col2"),all=TRUE)
#?? ID????? col2
#1?? 1 0.2002145
#2?? 2 0.6852186
#3?? 3 0.9168758
#4?? 4 0.2843995
#5?? 5 0.1046501
#6?? 6 0.7010575
#7?? 7 0.5279600
#8?? 8 0.8079352
#9?? 9 0.9565001
#10 10 0.1104530
You can also do this as:
?newdataset<-data.frame(ID=rep(NA,nrow(dataset)),col2=rep(NA,nrow(dataset)))
?newdataset[testindex,]<-testset
newdataset[-testindex,]<-trainset
?head(newdataset)
#? ID????? col2
#1? 1 0.2002145
#2? 2 0.6852186
#3? 3 0.9168758
#4? 4 0.2843995
#5? 5 0.1046501
#6? 6 0.7010575
A.K.
----- Original Message -----
From: Brian Feeny <bfeeny at mac.com>
To: r-help at r-project.org
Cc:
Sent: Saturday, December 1, 2012 11:04 PM
Subject: [R] How to re-combine values based on an index?
I am able to split my df into two like so:
dataset <- trainset
index <- 1:nrow(dataset)
testindex <- sample(index, trunc(length(index)*30/100))
trainset <- dataset[-testindex,]
testset <- dataset[testindex,-1]
So I have the index information, how could I re-combine the data using that back into a single df?
I tried what I thought might work, but failed with:
newdataset[testindex] = testset[testindex]
? object 'dataset' not found
newdataset[-testindex] = trainset[-testindex]
? object 'dataset' not found
Brian
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