I don't know if I understand (small example with R command wouuld help),
but, assuming your data.frame is called 'df'
subset(df, ID %in% ID_list)
Question, is ID_list a "list" or a vector, and are they really "numbers"
or "factors"?
Kyle. wrote:
R-help:
I have a variable ("ID_list") containing about 1800 unique numbers, and a
143066x29 data frame. One of the columns ("ID") in my data frame contains a
list of ids, many of which appear more than once. I'd like to find the
subset of my data frame for which "ID" matches one of the numbers in
"ID_list." I'm pretty sure I could write a function to do this--something
like:
dataSubset<-function(df, id_list){
tmp = data.frame()
for(i in id_list){
for(j in 1:dim(df)[1]){
if(i==df$ID[j]){
tmp<-data.frame(df[j,])
}
}
}
tmp
}
but this seems inefficient. As I understand it, the subset function won't
really solve my problem, but it seems like there must be something out there
that will that I must be forgetting. Does anyone know of a way to solve this
problem in an efficient way? Thanks!
Kyle H. Ambert
Graduate Student, Department of Medical Informatics & Clinical Epidemiology
Oregon Health & Science University
[EMAIL PROTECTED]
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