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loop problem
2 messages · Muhammad Azam, Jim Lemon
Muhammad Azam wrote:
Dear R members
I have a problem regarding storing the lists.
Let
L=number of distinct values of any predictor (say L=5)
P=number of predictors (say P=20)
g1 <- c()
for(i in 1:P){
if(L > 1){
for(j in 1:(L-1)){
g <- ....
g1[j] <- g
}
}
g2[]=sort.list(g1)
}
Now the question is: What should we use inside brackets of g2[....], whether "i" or some thing else? If L is not greater than 1 then there will be a "NULL" for g2. We don't want to store it in g2, so how can we handle this problem. Looking forward for some help. Thanks and
Hi Muhammad,
The first thing I would ask is "Why not store NULL in g2[[i]] if that
element is NULL?". If you do this:
for(i in 1:P) {
if(L > 1) {
g1<-rep(NA,L)
for(j in 1:(L-1)) g1[j]<-...
g2[[i]]<-sort.list(g1)
}
}
you will have fewer elements in g2 than you have sets of predictors and
will then have to match up the sets of predictors with the elements in
g2. I think you could just test for NULL
is.null(g2[[i]])
later on if you don't want to process these in a subsequent step.
Jim