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2
votes
2answers
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Filling in missing (blanks) in a data table, per category - backwards and forwards
I am working with a large data set of billing records for my clinical practice over 11 years. Quite a few of the rows are missing the referring physician. However, using some rules I can quite easily ...
8
votes
1answer
162 views
Select NA in a data.table in R
How do I select all the rows that have a missing value in the primary key in a data table.
DT = data.table(x=rep(c("a","b",NA),each=3), y=c(1,3,6), v=1:9)
setkey(DT,x)
Selecting for a particular ...
