[EMAIL PROTECTED] wrote:
Please excuse what I'm sure are very easy questions but I'm relatively
new to the R environment.
How can I view a range of list elements, but not all. e.g., I had a
matrix of patients and then split them out by patient id. I know I can
do patlist[[1]] to see the first one, but how can I view, say, the first
ten patients?
Use vector indexing on patlist such as
patlist[1:10]
which return a list of the first 10 elements.
Please read the docs on object indexing.
My other question is how to count how many patients have a record in
which a certain condition holds. E.g., I was trying something like this
to get a count:
ctr<-0
temp<-lapply(mylist, function(x){is.na(x$date1[1]) & !is.na(x$date2[1]))
ctr<-ctr+1})
No, lapply is NOT a loop, instead think vectorized:
## at first look at a logical vector, where the condition holds:
temp <- sapply(mylist, function(x)
(is.na(x$date1[1]) & !is.na(x$date2[1])))
ctr <- sum(temp) # and sum that vector
Uwe Ligges
But I don't think that's working correctly.
Thanks,
Steven
______________________________________________
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
______________________________________________
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
